Answer:
The answer would be E, gymnosperm
Explanation: Gymnosperms are an ancient group of plants that do not have flowers, they have a unique reproductive process, and produce seeds that are bare—, that is the seeds are not enclosed in a fruit!
what was surprising about pitchblende? what were the names of the two elements the curies discovered? how long did it take the curies to get a sample of radium big enough to be recognized? why did marie think the radium samples glowed?
Curies discovered Radium and Polonium.She took 4 years to get sample of radium.Marie think the radium sample glowed because Atoms in certain elements can break apart and release energy.
Why is it named pitchblende?The mineral has a pitch-black hue. German miners gave it the name "blende" because they thought it had several different metals mixed together. Radium, lead, helium, and a number of actinide elements are only a few of the radioactive substances found in pitchblende that can be linked to the decay of uranium.
What were the names of the two elements the curies discovered?As part of their investigation into pitchblende in 1898, the Curies discovered the elements polonium and radium.
In honor of Pierre, who sadly perished in a Paris street accident in 1906 at the age of only 46, the radioactivity unit was finally given the name "curie." The Curie family amassed an astounding number of Nobel Prizes as a result of Marie's continued labor. Together with Henri Becquerel, Pierre and Marie shared the physics award in 1903. In 1911, Marie won the chemistry Nobel Prize all by herself. Their daughter Irène married the French physicist Frederic Joliot, and she and her husband shared the 1935 Nobel Prize in Chemistry for discovering how to intentionally create radioactivity in a lab. Marie Curie passed away from radiation-induced leukemia at the age of 66 the previous year.
Why did marie think the radium samples glowed?Marie think the radium sample glowed because Atoms in certain elements can break apart and release energy.
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after separating your partition samples in the burettes, you add 3 drops of ferric chloride to the pre/post-partition salicylic acid solutions. you notice that the pre-partition solutions turned a much more vibrant purple color than their respective post-partition solutions. this suggests that:
The more vibrant purple color of the pre-partition solution suggests that the concentration of salicylic acid is higher in the pre-partition solution than in the post-partition solution because of the complex formed.
Ferric chloride (orange in color) interacts with phenolic hydroxy groups by creating a complex that has a strong purple color. The intensity of the color is proportional to the concentration of the phenol. Because salicylic acid contains a phenolic hydroxy group, its solution will also turn purple upon the addition of ferric chloride. If the pre-partition sample has a more vibrant color, then this means that the concentration of salicylic acid in it is significantly higher, which can then inform us on the effectiveness of the separation and partition process.
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australian tiger beetles can travel at 2.5 m/s. how long would it take a tiger beetle to run the length of a standerd football feild (109.7 m)
Australian tiger beetles can travel at 2.5 m/s . time take a tiger beetle to run the length of a standard football field (109.7 m) is 43.88 sec.
Given that :
speed of Australian tiger beetles = 2.5 m/s
distance of the football field = 109.7 m
to find out the time taken by a Australian tiger beetles to run the length of a standard football field 109.7 , we use the following formula:
speed = distance / time
Time = distance / speed
= 109.7 m / 2.5 m/s
= 43.88 sec
Thus, Australian tiger beetles can travel at 2.5 m/s . time take a tiger beetle to run the length of a standard football field (109.7 m) is 43.88 sec.
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Can someone please help me answer this question, im not sure if my answer is right, i dont understand the question. I need an explanation asap, please.
Answer:
nooooooooooooooooooooiooooooooob
Answer:
Ans is HCL as :
it reacts with limewater to produce bubbles of gas(CaCo3+2HCL -----> Cacl2+H20+Co2)
It is an acid so it turns blue litmus paper to red
When zinc reacts with hydrochloric acid, the reaction bubbles vigorously as hydrogen gas is produced. When hydrogen is near fire it burns with pop sound
It should also be noted that HCL is colorless
PLSSSS MARK AS BRAINLIEST
A sample of 0. 02 mol of oxygen has a temperature of 399 k and a volume of 5. 00 l. What is its pressure?.
The Pressure is 0.1309 atm.
What is Pressure?
The force applied perpendicularly to an object's surface per unit area about which that force has been distributed is known as pressure. In comparison to the surrounding pressure, gauge pressure is the pressure. Pressure is expressed using a variety of units. Some of these come from dividing a unit of force by a unit of area; the traditional unit of pressure inside the imperial and U.S. customary systems is the pound-force per square inch (psi), which is equivalent to one newton per square metre (N/m2) in the SI. The atmosphere (atm), which is equal to the this pressure, as well as the torr, which is defined as 1760 of this, are two other ways to express pressure.
Given,
Number of moles n = 0. 02 mol
Temperature T = 399 k
Pressure P = ?
Volume V = 5L
Ideal gas constant R = 0.08206L atm/mol K
Number of moles
n = P V/R T
0. 02 = P × 5/0.08206 × 399
0.02 = P × 5/ 32.741
0.65482 = P × 5
P = 0.1309 atm.
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How many moles of atoms are there in 8.674
x1023 atoms Ne?
Answer in units of mol.
Answer:
great question
Explanation:
I have 5 minutes if scientists could produce element 120, what predictions would you make about its reactivity
If scientists could produce element 120, its reactivity will be high as a result if the number of valence electrons present in its outermost shell.
What is an Element?This refers to a type of substance which can't be broken down into simpler substances by a chemical reaction and an example is Sodium.
In the case of element 120 if produced will belong to alkaline earth metals which have a valence electron of 2. This means that it needs to donate only two electrons to achieve a stable configuration which is therefore the reason why it will be highly reactive.
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A student determined the mass of a piece of magnesium ribbon. It was 3.0 g. She then burned the ribbon in oxygen and collected all the pieces of white ash (magnesium oxide). She measured the mass of the ash and it was found to be 5. 0 g. Does her experiment observe the law of conservation of mass? Explain.
Her experiment doesn't observe the law of conservation of mass
The law of conservation of mass states that in a chemical reaction mass is neither created nor destroyed and law of conservation of mass does not says that when any compound burned the ribbon in oxygen and collected all the pieces of white ash then its mass doesn't change its always constant so in the given data
A student determined the mass of a piece of magnesium ribbon and it was 3.0 g she then burned the ribbon in oxygen and collected all the pieces of white ash (magnesium oxide) and then mass of the ash is 0.5g so here when burn the compound the mass changes so this reaction does not followed the law of conservation of mass
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The barium hydroxide solution is used to titrate a perchloric acid solution of unknown concentration. Write a balanced chemical equation to represent the reaction between barium hydroxide and perchloric acid.
Balanced chemical equation to represent the reaction between barium hydroxide and perchloric acid is :
Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + 2 H₂O
These two substances would be your two reactants: perchloric acid is HClO₄ and barium hydroxide is Ba(OH)₂.
Barium perchlorate (Ba(ClO₄)₂) and hydrogen hydroxide (H₂O), often known as water, are the results of this double replacement process, in which the cations (Ba²⁺ and H⁺) swap places.
Thus the reaction would be :
Ba(OH)₂ + HClO₄ → Ba(ClO₄)₂ + H₂O
2 perchlorate ions on the left mean we need 2 perchloric acids on the right
Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + H₂O
Now we have 2 H⁺ ions and 2 OH⁻ ions on the right, so we need 2 H₂O on the left.
Ba(OH)₂ + 2 HClO₄ → Ba(ClO₄)₂ + 2 H₂O
Thus, it is the final balanced equation.
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What is the molarity of na+ ions in a solution of 25.0 ml of 1.25 m nacl and 145 ml of 0.550 m na2so4 and 30.0 ml of 0.225 m na3po4? assume the volumes are additive.
By taking into account the different numbers of sodium ions released by different salts upon dissociation, we can calculate that the final molarity of sodium salts is 0.1055 M.
To calculate the total molarity of the sodium ions in the new solution, we must calculate the number of moles of sodium ions in the first, second, and third solutions, add them up and divide them by the total volume of the new solution.
First solution - 1 mol of sodium chloride releases 1 mole of sodium ions upon dissociation, so the amount of sodium ions will be equal to the amount of sodium chloride:
c = n/V ⇒ n = c*V = 1.25 M * 0.0250 L = 0.03125 mol
Second solution - 1 mol of sodium sulfate releases 2 moles of sodium ions upon dissociation, so the amount of sodium ions will be double the amount of sodium sulfate:
n = 2c*V = 2 * 0.550 M * 0.145 L = 0.1595 mol
Third solution - 1 mol of sodium phosphate releases 3 moles of sodium ions upon dissociation, so the amount of sodium ions will be triple the amount of sodium phosphate:
n = 3c*V = 3 * 0.225 M * 0.0300 L = 0.02025 mol
The final molarity of sodium ions:
c = n/V = (0.03125 mol + 0.1595 mol + 0.02025 mol) / (0.0250 L + 0.145 L + 0.0300 L) = 1.055 M
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which of the following is not a part of the ideas john dalton proposed in his model
The following which is not a part of Dalton atomic theory is the properties of atoms of the same elements can be different . Thus option B is correct.
What is Dalton atomic theory?Dalton has proposed his theory in three parts and each part stated that
The first portion of his theory asserts that all stuff is made up of indivisible atoms.
According to the second section of the theory, all atoms of a given element have the same mass and characteristics.
Compounds, according to the third section, are combinations of two or more different types of atoms.
Dalton has given three laws
Law of conservation of massLaw of definite proportionLaw of multiple proportionThus, the following which is not a part of Dalton atomic theory is the properties of atoms of the same elements can be different . Thus option B is correct.
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Your question is incomplete, but your complete question was
which of the following is not a part of the ideas john dalton proposed in his model
A. All matter is composed of indivisible atoms.
B. The properties of atoms of the same element can be different.
C. Compounds form when atoms combine in whole number ratios.
D. An atom can neither be created nor destroyed.
IS THIS CORRECT??? I NEED HELPPP. IM GIVING BRAINLEST
Answer:carbon should be D, hydrogen should be A, magnesium is correct,oxygen is also correct.
Explanation:I’m sorry if this is wrong but I looked it up to see if it was correct or not
Which of the following has the highest conductivity ? a. 0.10 M copper (II) sulfate b. 0.10 M calcium hydroxide c. 0.10 M potassium iodide d. 0.10 M chloric acid e. 0.10 M nitrous acid
Answer:
Explanation:
Copper Sulfate
2. if you don't add all of the hcl to the test tube because you see all of the mg is used up but you still follow the directions in this lab report to calculate your volume of h2 produced how will it affect your value of r?
The rate of reaction r is measured by the amount of gas produced at a 10-second interval.
in this reaction magnesium and acids are gradually used up. however acid is in excess so it is mainly a loss of magnesium. that causes a change in the rate.
if the graph of the axis is in y and time in the x-axis. this shows this reaction fastest at the beginning. as the magnesium is used up the rate falls. when the reaction has stopped no more gas is produced.
What is the rate of reaction?The reaction rate or rate of reaction is the speed at which a chemical reaction takes put, characterized as relative to the increase within the concentration of a product per unit of time and to the decrease within the concentration of a reactant per unit of time. Response rates can shift drastically. For case, the oxidative rusting of press beneath the Earth's atmosphere could be a slow reaction that can take numerous a long time, but the combustion of cellulose in a fire could be a response that takes place in divisions of a second. For most responses, the rate diminishes as the reaction proceeds. A reaction's rate can be decided by measuring the changes in concentration over time.To learn more about reaction rate, refer;
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how do two sublevels of the same principal energy level differ from each other?
Two sublevels of the same principal energy level differ from each other through shape and size.
There are mainly 4 energy level s, p, d and f.
The s level has one orbital and one orbital have two electrons. So the maximum number of electron in s sublevel is 2.
The p level has three orbital and one orbital have two electrons. So the maximum number of electron in s sublevel is 6.
The d level has five orbital and one orbital have two electrons. So the maximum number of electron in s sublevel is 10.
The f level has 7 orbital and one orbital have two electrons. So the maximum number of electron in s sublevel is 14.
They may be differ in magnetic level.
Thus, we concluded that Two sublevels of the same principal energy level differ from each other through shape and size.
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Draw the structure of NO3− . Draw the ion by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons. Use square brackets to denote the overall charge.
Structure of NO₃⁻ has overall charge [NO₃]⁻ is -1
The molecular structure of a compound depicts the atoms of a molecule with their charges and their lone pairs of electrons and this is also called as lewis dot structure where the molecules are drawn showing their bonds represented by lines or dots and the non-bonding pairs of electrons represented by dots not between atoms and has overall charge [NO₃]⁻ is -1
Structure of [NO₃]⁻ on by placing atoms on the grid and connecting them with bonds include all lone pairs of electrons are shown below
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the ksp for mn(oh)2 is 2.0 x 10-13. at what ph will mn(oh)2 begin to precipitate from a solution in which the initial concentration of mn2 is 0.10 m? note: ph
You are aware that the dissociation equilibrium for Manganese hydroxide appears as follows.
Mn(OH)2(s]⇌Mn2+(aq]+2OH−(aq]
The formula for the solubility product constant, Ksp, is Ksp=[Mn2+][OH].2
Rearrange to determine the hydroxide anions' concentration [OH]=Ksp/[Mn2+].
Enter your values to obtain
[OH−]=√1.0⋅10−110.1\s=√1.0⋅10−10=10−5M
As you are aware, you may calculate the solution's pOH using the concentration of hydroxide anions: pOH=log([OH]; pOH=log(105)=5
Lastly, make use of the correlation between pH and pOH at room temperature.
To determine the pH of the solution, use pH=145=9 + pOH.
As a result, the solution will be unsaturated for pH values lower than 9. The solution gets saturated and the magnesium hydroxide begins to precipitate after the pH of the solution reaches 9.
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Write the balanced formula, complete ionic, and net ionic equations for each of the following acid–base reactions.
The ionic equation of the reaction of HNO₃ and aluminum hydroxide:
3 H⁺ (aq) + Al(OH)₃ (s) → 3H₂O (l)
What are the net ionic equations?
The net ionic equation of a reaction is an equation that represents only those elements, ions, or compounds, that directly contributed to the occurrence of the chemical reaction.
The ions which do not participate are mentioned in the complete ionic equation but eliminated from the net ionic equation and are called spectator ions.
The balanced chemical equation of the reaction of nitric acid and aluminum hydroxide.
3 HNO₃ (aq) + Al(OH)₃ (s) → 3H₂O (l) + Al(NO₃)₃ (aq)
As the aluminum hydroxide (Al(OH)₃) does not dissolve in nitric acid. In the complete ionic equation, it does not dissociates into ions.
3 H⁺ (aq) + 3NO₃ (aq) + Al(OH)₃ (s) → 3H₂O (l) + Al³⁺ (aq) + 3NO₃⁻ (aq)
In the complete ionic equation, the nitrate ions appear unchanged on both sides of the equation. Therefore, the nitrate ions do not participate in the reaction and can be eliminated from the ionic equation to get the net ionic equation.
3 H⁺ (aq) + Al(OH)₃ (s) → 3H₂O (l)
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Your question is incomplete, the most probably complete question was,
Write the balanced, complete ionic, and net ionic equations for the following acid-base reaction.
HNO₃ (aq) + Al(OH)₃ (s) →
the two electrodes of an electrolytic cell are placed in a sample of molten zinc iodide. after a time, reddish-brown i2(s) begins to form at one electrode while gray zn(s) deposits on the other.
In the given electrolytic cell setup having molten zinc iodide as the electrolyte, reduction of zinc ions to gray coloured zinc occurs at the cathode, whereas iodide ions get oxidized to reddish-brown iodine at the anode.
An electrolytic cell is a type of electrochemical cell that uses an external source of electrical energy to power a chemical process that would not occur otherwise. This contrasts with a galvanic cell, which serves as a power source and the cornerstone of a battery.
Any apparatus in which electrical energy is changed into chemical energy or vice versa is an electrolytic cell. Such a cell normally consists of two electrodes, which can be metallic or electronic conductors, kept apart from one another and in contact with an electrolyte, which is commonly an ionic substance that has been dissolved or fused.
In the given setup, the molten zinc iodide is the electrolyte, and the half reactions occurring at the two electrodes of the electrolytic cell are:
Half reaction at the cathode:
[tex]Zn^{2+} (l) + 2e^- \rightarrow Zn (s)[/tex]
Half reaction at the anode:
[tex]2I^- (l) \rightarrow I_2 (s) + 2e^-[/tex]
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sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride. In a particular experiment, the percent yield is 79%. this means that in this experiment, a 7.90g sample of fluorine yields how many grams of sulfur hexafluoride
A certain experiment had a yield of 79.0%, expressed as a percentage. This indicates that the amount of SF₆ that can be produced from a fluorine sample that is 7.90 grams is seven grams.
How does one go about creating hexafluorous sulfur?Sulfur A disparity agent, hexafluoride is an inorganic fluorinated inert gas composed of six fluoride atoms bonded to one sulfur atom. It has the potential to have diagnostic action when it is imaged.
Therefore, 7 grams of SF₆ can be produced from a fluorine sample.
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wrapping a hot potato in aluminum foil significantly reduces the rate at which it cools by question 17 options: melting. conduction. evaporation. condensation.
The correct answer is option C: Evaporation
Wrapping a hot potato in aluminum foil significantly reduces the rate at which it cools by evaporation.
It is because, the aluminum foil serves as a reflector of infrared radiations or IR radiations.
The surface of the aluminum foil reflects back the radiations and does not allow them to escape to the surrounding.
Thus, in this way, the potato, wrapped in the foil, cools down at a slow rate as the radiation are trapped inside it and keep the potato warm and hot for a longer time period.
On the contrary, if the radiations were to escape, then the potato would cool down rapidly by evaporation.
Evaporation refers to the transformation of a matter from one phase to another i.e. from hot to cool phase, thereby, the reflection of radiations does not let the potato cool over time.
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Balanced chemical reactions obey the law of
conservation of mass
a. True
b. False
Answer:
True
Explanation:
A balanced chemical equation always obeys the law of conservation of mass. According to this law, the mass of products must be equal to the mass of reactants. A reaction is said to be balanced when the total mass of atoms on both sides of the chemical reaction is equal.
what are the 3 specific ways an object can accelerate
Answer:
increasing speed, decreasing speed, or a change in direction.
Explanation:
i hope this helps
How would you prepare a 1 L solution of 3 M MgO?
Put 3 grams of MgO in the beaker and add enough water to reach the 1 L mark.
Put 120 grams of MgO in the beaker and add exactly 1 L of water.
Put 120 grams of MgO in the beaker and add enough water to reach the 1 L mark.
Put 3 grams of MgO in the beaker and add exactly 1 L of water.
Answer: (Option C) We need to 120 g of MgO in the beaker and add enough water to reach the 1 L mark.
Explaination: Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
Which is more reactive boron or neon
If copper (ii) sulfate solution and an iron nail are in contact, a replacement reaction occurs. what would the products of the reaction be? 2fe 3cuso4 → ? 2fe 3cuso4 fe2(so4)3 3cu 2fe 3cu 3s 3o4
The result of the replacement reaction [tex]2Fe +3 CUSO_{4}[/tex] is [tex]2Fe(SO_{4} )_{3} + 3 Cu.[/tex]
Reaction[tex]2Fe +3 CUSO_{4} ----------- > 2Fe(SO_{4} )_{3} + 3 Cu.[/tex]
the above reaction is a Displacement reaction.
Displacement reaction.
When an atom or group of atoms in a molecule is replaced by another atom, this is referred to as a displacement reaction. For instance, copper metal is displaced when iron is added to a solution of copper sulfate.
What causes a displacement response to happen?When one element replaces another in a compound, it causes a single displacement reaction. Neither metal nor a nonmetal may be used as a substitute for another metal. Only a more reactive component of the chemical it reacts with can take the place of the other component.
How about an illustration of double displacement?A new insoluble ionic compound is created by a precipitation reaction between two aqueous ionic compounds. The reaction between lead (II) nitrate and potassium iodide to produce (soluble) potassium nitrate and (insoluble) lead iodide is illustrated below.
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An atom of bromine has 35 electrons. These electrons are present in energy shells around
the nucleus. What is the electron configuration of bromine?
a. 2,8, 18, 1
b. 2, 8, 18,7
c. 2,8,8,17
d. 2,8, 18, 35
Answer:
b. 2, 8, 18,7
Explanation:
Shell 1 = 2
Shell 2 = 8
Shell 3 = 18
Shell 4 = 7
A 118.0 g sample of a compound contains 72.0 g of C. 18.0 g of H, and 28.0 g of N.
Which of the following is the empirical formula of the compound?
The empirical formula of the compound with 72.0 g of C. 18.0 g of H, and 28.0 g of N is C₃H₉N.
How to calculate empirical formula?Empirical formula of a compound indicates the ratios of the various elements present in a compound, without regard to the actual numbers.
The empirical formula of a compound can be calculated as follows:
C = 72.0g H = 18.0g N = 28.0gFirst, we divide by the atomic mass of each element as follows:
C = 72.0g ÷ 12 = 6molH = 18.0g ÷ 1 = 18 molN = 28.0g ÷ 14 = 2molNext, we divide by the smallest mole as follows:
C = 6mol ÷ 2 = 3
H = 18 mol ÷ 2 = 9
N = 2mol ÷ 2 = 1
The empirical ratio is 3:9:1, hence, it can be said that the empirical formula is as follows: C₃H₉N.
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poopxpoop equals 1111111111111111111222222222222222233333333333333333333 go
A photon has an energy of 8.42 eV.
What is its frequency?
Hint: 1 eV = 1.60 x 10-19 J
Answer: The frequency is given by:
Photon energy is 8.42 eV
By Planck's relation:
E= hv (h is the Planck's constant and v is the frequency)
v= E/h
1 eV = 1.60×10-19J
E= 8.42× 1.6×10-19 Joules
h = 6.62×10-34 Joule/Hz
Substituting the values in the above formula
v = (8.42×1.6×10-19) /(6.62×10-34)
Frequency = 2.035×10(power) +15 Hertz
Explanation:
Firstly we convert energy into Joules then we have to just substitute given values to get our answer. The equation or formula we are using to solve this particular question is Planck's relation.