Answer:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom.example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell. We can write the configuration of oxygen's valence electrons as 2s²2p⁴.
what is Brownian motion
Answer: the erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium. Brownian motion, or pedesis, is the random motion of particles suspended in a medium. This pattern of motion typically consists of random fluctuations in a particle's position inside a fluid sub-domain, followed by a relocation to another sub-domain. Brownian motion, also called Brownian movement, any of various physical phenomena in which some quantity is constantly undergoing small, random fluctuations. It was named for the Scottish botanist Robert Brown, the first to study such fluctuations (1827).
Hope this helps...... Stay safe and have a Merry Christmas!!!!!!!!! :D
Explanation:
Answer:
to and fro motion is called brownian motion
Which type of rock forms when an existing rock changes under extreme pressure and intense heat?
A
igneous
B
sedimentary
C
metamorphic
Answer:
c
Explanation:
metamorphic rocks
Answer:
C. Metamorphic
Explanation:
Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2
What mass of carbon monoxide is needed to react with 1.80g Fe2O3
Mass of carbon monoxide : 0.95 g
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂
MW Fe₂O₃ : 159,69 g/mol
mol Fe₂O₃ :
[tex]\tt \dfrac{1.8}{159.69}=0.0113[/tex]
mol ratio Fe₂O₃ : CO = 1 : 3, so mol CO :
[tex]\tt 3\times 0.0113=0.0339[/tex]
mass CO (MW = 28,01 g/mol) :
[tex]\tt m=mol\times MW\\\\m=0.0339\times 28.01\\\\m=0.950~g[/tex]
Select the correct answer.
Which of the following might cause chemical contamination when used near food?
A.
furniture polish
B.
steel can
Ос.
glass container
OD. plastic bag
Reset
Next
Write a report on waves
Answer:
The epic emotional journey of a suburban African American family as they navigate love, forgiveness and coming together in the wake of a tragic loss.
Explanation:
hope thsi helps if so please brainliest
Merry Christmas
Which state of matter has neutral particles that bounce off one another as they collide? A: Gas B: Liquid C: Plasma D: Solid
Answer:
Gas
Explanation:
In the original mixtures, test tube 1 contained magnesium and a zinc compound, and test tube 2 contained zinc
and a magnesium compound. A similar relationship exists between test tubes 3 and 4 and between test tubes 5
and 6. Compare what took place in each corresponding pair of test tubes. What general conclusion can you draw?
Answer:
Magnesium in tube 3 and copper in tube 5 became compounds
If each of the test tubes contained a less reactive compound and a more reactive element or less reactive element and more reactive compound , in first case chemical change of displacement reaction will occur while in second case no reaction will occur as zinc exists as an element.
What is chemical change?Chemical changes are defined as changes which occur when a substance combines with another substance to form a new substance.Alternatively, when a substance breaks down or decomposes to give new substances it is also considered to be a chemical change.
There are several characteristics of chemical changes like change in color, change in state , change in odor and change in composition . During chemical change there is also formation of precipitate an insoluble mass of substance or even evolution of gases.
There are three types of chemical changes:
1) inorganic changes
2)organic changes
3) biochemical changes
During chemical changes atoms are rearranged and changes are accompanied by an energy change as new substances are formed.
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The cost of table of sugar C12 H22 O11 is RS 24 per kg calculate it cost mole
Answer:
One mole of sugar is a considered as atomic mass. The atomic mass of sugar is 342 g. Rate of 1 kg of sugar is 40 Rs. Thus, the rate of 342 gram of sugar= 40x342/1000 = 13.68 Rupees
Explanation:
3 elements that have similar properties
Answer:The elements in the first column of the Periodic Table (other than hydrogen) are known as Group 1A metals, or alkali metals. When you compare the chemical properties of these elements (lithium, sodium, potassium, rubidium, cesium, and francium), what you'll notice is that they are all remarkably similar.
Explanation:
Lithium, sodium, and potassium are the three elements from group number 1 of the periodic table that has similar chemical and physical properties, these group 1 metals are also known as alkali metals.
What is the atomic number?The total number of protons present in an atom is known as the atomic number of that atom. The atomic number has no correlation either with the number of neutrons or the number of electrons present inside an atom.
Group 1 metals, often known as alkali metals, are a trio of elements from the periodic table that have similar chemical and physical characteristics. They are lithium, sodium, and potassium.
Thus, Lithium, sodium, and potassium are the three elements from group number 1 of the periodic table that has similar chemical and physical properties.
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Describe the process of dimensional analysis and explain why it is so useful in chemical problem solving.
Answer:
Dimensional Analysis (also called Factor-Label Method or the Unit Factor Method) is a problem-solving method that uses the fact that any number or expression can be multiplied by one without changing its value. It is a useful technique.
.What does the changing the Aperture do when taking a photo? *
4.What effect can you get from using a slow shutter speed? *
5.What effect can you create by using a quick shutter speed?
Answer:
Slower shutter speeds like 1/60 second and slower cause a blurring effect. If you want to take a picture using a slow shutter speed, it is best to mount the camera on a tripod and use image stabilization (such as SteadyShot® technology) to reduce the chance of any unwanted camera movement.
The first big effect of it is motion blur. If your shutter speed is long, moving subjects in your photo will appear blurred along the direction of motion. ... If you use an especially fast shutter speed, you can eliminate motion even from fast-moving objects, like birds in flight, or cars driving past.
Explanation:
Example of market structures of monopoly
Answer: A monopoly is the absence of competition in the market.
Explanation:
In such circumstances, the market creates a monopoly of one producer who takes huge capital and dictates prices. An example of a monopoly on the market is the existence of only one company that makes up the entire economic branch. In such circumstances, the monopolist can increase the product's price without losing the entire sale, i.e., operating successfully. In that situation, the monopolist remains the only one on the market, and the competition has no access to the market.
Help I’m not sure what to do
NEED HELP ASAP!!
(04.04 LC)
Which statement is true about the products of cellular respiration?
They contain oxygen.
They contain glucose.
They become the products of photosynthesis.
They become the reactants of photosynthesis.
Answer:
They contain oxygen
hope it helps
A complex absorbs photons with an energy of 4.10×10^−19 J. What is the wavelength of these photons? If this is the only place in the visible spectrum where the complex absorbs light, what color would you expect the complex to be?
Answer:
483 nm corresponds to blue light hence the complex will appear orange.
Explanation:
Using the formula;
E= hc/λ
Where;
E = energy of the photon
h = Plank's constant (6.6*10^-34Js)
c = Speed of light (3*10^8 ms-1)
λ = wavelength
λ = hc/E
λ = 6.6*10^-34 * 3*10^8/4.10×10^−19
λ = 4.83 * 10^-7 or 483 nm
483 nm corresponds to blue light
Using the colour wheel approach, if a complex absorbs blue light, then it will appear orange.
Which salt solution is most likely to be colored?
Answer:
K2CrO4 (aq)
Explanation:
previous nect
What is electrons configuration for arsenic ?
Answer:
[Ar] 3d¹⁰ 4s² 4p³
Explanation:
so...... ur welcome
how many moles is 8.72x10^24 atoms? can you solve the equation too?
Answer:
14.49 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{8.72 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 14.48504...[/tex]
We have the final answer as
14.49 molesHope this helps you
what substance has a mass of 9.5 grams and a volume of 2.1 cm^3?
SUBSTANCE.
Explanation:
Given parameters:
Mass = 9.5g
Volume = 2.1cm³
Unknown:
What kind of substance is this = ?
Solution:
To determine the kind of substance given, we need to find its density from the given parameters.
The density of a substance can tell us about such body.
Density is an intensive property and it is the mass per unit volume.
Density = [tex]\frac{mass}{volume}[/tex]
Now insert the parameters and solve;
Density = [tex]\frac{9.5}{2.1}[/tex] = 4.52g/cm³
The substance will most likely be a solid.
Help plz:))) I’ll mark u brainliest ASAP 10 points
Answer: I believe it’s the second one
(F)
Explanation:
A kind of sedimentary rock formed from plant material over a long period of time is __________.
a.
limestone
b.
cementation
c.
coal
d.
compaction
Please select the best answer from the choices provided
A
B
C
D
Answer:
Cementation
Explanation:
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at the Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place :)
Answer:
Coal
Explanation:
Coal is formed from plants trapped in dust and dirt for a long time, so coal would fit plant material, and it also takes a long time to make coal, that's why it will run out at some point
Which of the following bonds would be the most polar without being considered ionic? a. Mg-o b. C-O C. N-O d. Si-O
Answer:
the answer is c hope this helps
Explanation:
N-O is the most polar without being considered ionic. Hence, option C is correct.
What is an ionic bond?An ionic bond is formed by the complete transfer of some electrons from one atom to another.
Bonds between carbon and other elements such as oxygen or nitrogen are polar. The polarity of a bond depends upon the electronegativities of the bonded atoms.
Hence, option C is correct.
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Directions: Read the paragraph and identify the correct words that fit in the given sentences
inside the box. Write your answer in a separate sheet of paper.
Elements
non-metal
chemical process components
metal
more
properties
metalloids
properties
Compounds
one
chemical
are made up of
Elements and Compounds are all around us. (1)
utumn or atoms of the same kind. They are the simplest type of matter and cannot
be broken down into components. Each element is made entirely from (2)
type of atom. Each element is unique and no two elements have the same set of
(3)
Some are in the same state but they have (4)
properties.
Some elements are (5) like iron, gold and silver. Others are (6) like
Nitrogen, Oxygen and Ilydrogen. There are elements that are (7)
like
Boron. Silicon and Germanium.
(8)
are combination of (9)
or (10)
elements
like water which is a combination of Hydrogen and Oxygen; salt which is made
up of sodium and chlorine; and rusts formed when an iron reacts with oxygen.
Compounds can be broken down into it's (11) through a (12)
process and formed when two elements are combined together. It has unique
properties that are different from the properties of the elements that make them
Answer:
1. Elements
2. one
3. properties
4. Chemical
5. metal
6. non-metal
7. metalloids
8. Compounds
9. one
10. more
11. components
12. chemical process
Explanation:
In the given paragraph a brief about the difference between element and compound is given.
Elements are made up of the same type of atoms and each element is made up of one atom, that is they cannot be broken down into any other substance. Each element is different from each other due to its properties, though some have the same physical properties but are different in chemical properties. Elements can be classified as metals such as iron and silver, non-metals such as oxygen and hydrogen, and metalloids such as boron and silicon.
Compounds are a combination of one or more elements such as water and salt. Compounds can be easily broken down into components through a chemical process.
Hence, the correct answer is:
1. Elements
2. one
3. properties
4. Chemical
5. metal
6. non-metal
7. metalloids
8. Compounds
9. one
10. more
11. components
12. chemical process
A 25 cm sample of dilute sulfuric acid contains 0.025 moles of the acid.
What is the hydrogen ion concentration in the solution?
A. 0.2 mol/dm3
B. 0.05 mol/dm3
C. 1.00 mol/dm3
D. 2.00 mol/dm3
Answer:B. 0.05 mol/dm3
Explanation:
The hydrogen ion concentration in the solution is 2 mol/dm³
The correct answer to the question is Option D. 2 mol/dm³
We'll begin by calculating the molarity of the solution.
Volume = 25 cm³ = 25 / 1000 = 0.025 dm3
Mole of H₂SO₄ = 0.025 mol
Molarity of H₂SO₄ =?Molarity = mole / Volume
Molarity of H₂SO₄ = 0.025 / 0.025
Molarity of H₂SO₄ = 1 mol/dm³Finally, we shall determine the concentration of Hydrogen ion in the solution.H₂SO₄(aq) —> 2H⁺(aq) + SO₄²¯(aq)
From the balanced equation above,
1 mole of H₂SO₄ contains 2 moles of H⁺.
Therefore,
1 mol/dm³ H₂SO₄ will also contain 2 mol/dm³ H⁺.
Thus, the concentration of Hydrogen ion in the solution is 2 mol/dm³
The correct answer to the question is Option D. 2 mol/dm³
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A 2.52 L container of oxygen gas at 28.6 °C is heated to 45.9 °C. Assuming that the volume of the container can vary, what is the new volume of the gas?
Answer:
4.04433566 L (433566 repeating)
Explanation:
2.52 is divided by 28.6 is 0.0881118 (881118 repeating). multiply 0.0881118 (881118 repeating) by 45.9 to get 4.04433566 L (433566 repeating).
Is it balanced or unbalanced
How much water would need to be added to 1092 mL of a 54.7 M NaCl solution to make a 0.25 M solution?
Answer:
237.8L of water would need to be added.
Explanation:
The first thing to do is to identify that the equation to be used is M1V1=M2V2. (This equation works because it turns everything into moles which can then be compared).
Then figure out what information you have and what is being found. In this case:
M1 = 54.7 M
V1 = 1092 mL = 1.092 L
M2 = 0.25 M
V2 = unknown
Then solve the equation for whatever you are trying to find.
M1V1=M2V2
V2=M1V1/M2
Now you need to plug everything in.
V2=(54.7M*1.091L)/0.25M
V2=238.93L
That means that the solution needs a volume of 238.7L to gain a molarity of 0.25M but the starting solution already had a volume of 1.092 L meaning that to find the amount of solvent that needs to be added you just subtract the starting volume by the volume that the solution needs to be.
238.93L - 1.091L = 237.8L
Therefore the answer is that 237.8L needs to be added to a 1.092L 54.7M NaCl solution to make the concentration 0.25M.
I hope this helps. Let me know if anything is unclear.
if an atom has 15 protons and a mass of 31 how many neutrons will it have
Answer:
16 neutrons
Explanation:
now that protons are equal to electrons, there are 15 electrons. The mass is equal to 31.0, which is the ≡ of protons and ≡ neutrons added together. To find the number of neutrons, subtract the atomic # from the total mass #. 31-15=16 this would be equal to 16 now that the atomic has 31 and the mass is 15 subtract them ... you would get 16 neutrons inside the nucleus.
hope this helped ((((: if it did then please mark brainliest and have a wonderful day d:
Answer:
16
Explanation:
To find the neutrons, it's always mass-atomic number. Since the atomic number for an atom is always the protons, it's really mass-protons.
31-15=16
Which of the following has a tetrahedral molecular geometry?
NH3
CCl4
H2O
CO32-
Answer:
CCl₄
Explanation:
The molecule with a tetrahedral molecular geometry is CCl₄.
We know this according the valence shell electron pair repulsion theory.
To have a tetrahedral shape, a molecule must be made up of 4 bond pairs and no lone pairs.
This is clearly exhibited in the compound given;
The central atom has 4 valence electrons which is completed bonded by 4 chlorine atom.
There is no lone pair but we have 4 bond pairs and a tetrahedral shape is formed.
A system gains 687 kJ of heat, resulting in a change in internal energy of the system equal to 156 kJ. How much work is done?
1. Work was done by the system.2. Work was done on the system.
Answer:
w = -531 kJ
1. Work was done by the system.
Explanation:
Step 1: Given data
Heat gained by the system (q): 687 kJ (By convention, when the system absorbs heat, q > 0).Change in the internal energy of the system (ΔU°): 156 kJStep 2: Calculate the work done (w)
We will use the following expression.
ΔU° = q + w
w = ΔU° - q
w = 156 kJ - 687 kJ
w = -531 kJ
By convention, when w < 0, work is done by the system on the surroundings.