Answer:
Because its the basic building block of life
Explanation:
Carbon is essential to life since it is present in nearly all molecules in the body. like, sugars, DNA, proteins, lipids, and so on. Except for water though.
The half life of iodine-131 is 8.040 days. What percentage of an iodine-131 sample will remain after 40.20 days?
The percentage of an iodine-131 sample that will remain after 40.20 days is 3.125%
We'll begin by calculating the number of half-lives that has elapsed. This can be obtained as follow:Half-life (t½) = 8.040 days.
Time (t) = 40.20 days
Number of half-lives (n) =?[tex]n = \frac{t}{t_{1/2}} \\\\n = \frac{40.20}{8.040}\\\\[/tex]
n = 5Thus, 5 half-lives has elapsed.
Finally, we shall determine the percentage of an iodine-131 sample that remains. This can be obtained as follow:Number of half-lives (n) = 5
Percentage remaining =?[tex]N = \frac{1}{2^{n} } * N_{0} \\\\N = \frac{1}{2^{5} } * N_{0} \\\\N = \frac{1}{32} * N_{0}\\\\[/tex]
Divide both side by N₀
[tex]\frac{N}{N_{0}} = \frac{1}{32} \\\\\frac{N}{N_{0}} = 0.03125\\\\[/tex]
Multiply by 100 to express in percent
[tex]\frac{N}{N_{0}} =[/tex] 0.0312 × 100
= 3.125%Therefore, the percentage of an iodine-131 sample that remains is 3.125%
NOTE:[tex]\frac{N}{N_{0}}[/tex] => Fraction remaining
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An atom of beryllium can be represented as 9/4Be.
Describe the structure of the beryllium atom.
in your answer make reference to the number of subatomic
particles and where they are found in the atom
a) Two ways to create a positive ion:
Positive ions are formed by atoms or molecules suffering an inelastic collision with an energetic electron in which an electron is lost from the atom or molecule (electron impact ionization). The degree of ionization of the plasma depends strongly on the electron density and energy distribution in the gas.
(BRAINLIEST FOR CORRECT ANSWER) How does the particle structure of a solid affect its shape, volume, and compressibility?
Answer:
A solid's particles fit closely together. The forces between the particles are so strong that the particles can not move freely; they can only vibrate. This causes a solid to be a stable, non-compressible shape with a definite volume.
Explanation:
I honestly don't know if that's right...
How many moles of sodium chloride are in a 321.8 g sample?
Answer:
One mol of NaCl (6.02 x1023 formulas) has a mass of 58.44 g.
The number of moles of sodium chloride in a 321.8 g sample is 5.5 moles. Details about number of moles can be found below.
How to calculate number of moles?The number of moles of a substance in a particular mass of that compound can be calculated as follows:
no of moles = mass ÷ molar mass
molar mass of NaCl = 58.5g/mol
No of moles of sodium chloride = 321.8g ÷ 58.5g/mol
no of moles = 5.5 moles
Therefore, the number of moles of sodium chloride in a 321.8 g sample is 5.5 moles.
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both magnesium rod and aluminium rod can be used as conductor of electricity. Why?
Answer:
Both Magnesium and aluminium rods are metals, hence they allow flow of charged electrons due to high drift velocity.
Explanation:
• An electric conductor is material which allows flow of electric current.
[tex].[/tex]
The Magnesium (Z = 12) is an alkaline earth metal and the Aluminium (Z = 13) is a metal in the Boron Group. One characteristic of the metals is that they have facility to lose electrons, wich means facility to conduct electricity.
Moreover, the metals are ductile, so it is easy to turn them into wires. For example, the light poles has wires made by copper because the copper is another metal, so its have the same properties as indicated above.
I hope I've helped. =D
Enjoy your studies! \o/
Magnesium has three isotopes: Magnesium-24 with a mass of 23.98504 amu and an abundance of 78.70%, magnesium-25 with a mass of 24.98584 amu and an abundance of 10.13%, and magnesium-26 with a mass of 25.98259 amu and an abundance of 11.17%.
Without doing the calculations, should the atomic mass of magnesium be closer to 25, 26, or 27 amu? Explain how you know.
Your grandmother wants to build a small garden in her backyard.She lives near a city and doesn't have a large budget for this.Should she use an organic or inorganic fertilizer?
Answer:
So if you are buying, Inorganic is cheaper but at the cost of it's quality, organic fertilizer is better quality that's why it is more expensive, both work so if you want the cheaper option that's fine it still works
Explanation:
12. Using the two equations E = hv and c= lv, derive an
equation expressing E in terms of h, c, and \.
[tex]\\ \sf\longmapsto c=\lambda v[/tex]
[tex]\\ \sf\longmapsto v=\dfrac{c}{\lambda}[/tex]
Now
[tex]\\ \sf\longmapsto E=hv[/tex]
Put value of v found before
[tex]\\ \sf\longmapsto E=\dfrac{hc}{\lambda}[/tex]
WILL MARK AS BRAINLIEST IF CORRECT
Answer:
I don't know what is the actual answer
Taku mixed some water and juice crystals to make a fruit drink.
(a) The solute is
(b) The solvent is
According to the concept of solubility, thing which dissolves is solute and in which it is dissolved is solvent , hence juice crystals are solute and water is solvent.
What is solubility?Solubility is defined as the ability of a substance which is basically solute to form a solution with another substance. There is an extent to which a substance is soluble in a particular solvent. This is generally measured as the concentration of a solute present in a saturated solution.
The solubility mainly depends on the composition of solute and solvent ,its pH and presence of other dissolved substance. It is also dependent on temperature and pressure which is maintained.Concept of solubility is not valid for chemical reactions which are irreversible. The dependency of solubility on various factors is due to interactions between the particles, molecule or ions.
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How much heat is needed to vaporize 10.0 grams of water?
Plz answer these
Ill mark you brainliest
Answer:
I don't do chemistry
Explanation:
sorry
What element has the electron configuration 1s22s22p63523p64523d4?
A.Chromium (Cr)
B.Magnesium (Mg)
C.Manganese (Mn)
D.Iron (Fe)
Explanation:
It's none of these.
Cr- 1s2 2s2 2p6 3s2 3p6 4s1 3d5
Mg- 1s2 2s2 2p6 3s2
Mn - 1s2 2s2 2p6 3s2 3p6 4s2 3d5
Fe- 1s2 2s2 2p6 3s2 3p6 4s2 3d6
I think there's a mistake in the question.
Which statements about nuclear fission and nuclear fusion are true? Select the two correct answers. (1 point)
They both occur in the nucleus of an atom
They both involve two atoms fusing into one atom
They both reloase large amounts of energy
They both involve one atom splitting into two atorns
Statements that describes nuclear fission and nuclear fusion as regards this question are:
C: They both release large amounts of energy
D:They both involve one atom splitting into two atoms.
Both fission and fusion can be regarded as nuclear reactions that brings about production of energy. However they have different applications.Fission can be explained as the splitting of a heavy as well as unstable nucleus into two nuclei , but this nuclei are lighter compare to the mother nucleus.
Fusion on the other hand can be regarded as a process involving two light nuclei coming together to form one and then release vast amounts of energyFor instance, uranium will undergo fission to produce strontium and krypton nuclei
Therefore, option C, D are right.
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Answer:
C: They both release large amounts of energy
D: They both involve one atom splitting into two atoms
Calcium carbonate, Caco is able to remove sulfur dioxide, SO, from waste gases by a reaction in
which they react in a 1:1 stoichiometric ratio to form equimolar amounts of Caso, When 255 gof
CAC, reacted with 135 g of So, 198 g of caso, were formed. Determine the percentage yield of Caso3
Answer: Detailed problem with lots of assumptions. Please see below. Percent yield is 100% (!?, so check my work).
Explanation:
Some information is missing from the problem statement. I'll make some assumptions to solve the problem, so this answer depends on those assumptions.
"Calcium carbobnate" is CaCO3, not CaCO, which is obtained by calcining (heating) CaCO3:
CaCO3 = CaO + CO2
The CaO can then be reacted with SO2 to form calcium sulfate, CaSO4 (not CaSO, as per the following balanced equation:
2CaO + 2SO2 + O2 = CaSO4
[Note: It also reacts with any SO3 molecules bouncing around, as does happen in flue gases to also form CaSO4]
The following assumes we have 255 grams of CaCO3, not CAC, whatever that stands for.
We have 135g of SO2, not SO.
This also assumes that it is CaSO4 that is produced (not CaSO), 198 grams.
Since is a two step reaction sequence, we need to first calculate the moles of Ca) produced from the CaCO3. It is a 1:1 molar ratio, and we have (255g/100.1g/mole) = 2.548 moles of CaCO3. This will produce 2.548 moles of CaO, for use in the second reaction.
2CaO + 2SO2 + O2 = 2CaSO4
This tells us we'll produce 1 mole of CaSO4 for every 2 moles of CaO, a 1:2 ratio. It also states that 2 moles of SO2 are consumed for every 2 moles CaO, a 1:1 ratio.
We have 2.548 moles of CaO, so would need the same moles of SO2 to fully react. However, we only have (135g/64.1 g/mole) = 2.107 moles of SO2. The SO2 will be the limiting reagent, so the theorectical yield will be based on this reactant, which will consume 2.107 moles of CaO, leaving 0.44 moles (24.7 g) of CaO behind.
The balanced equation tells us that 2.107 moles of CaO should produce 2.107 moles of CaSO4, which is (2.107moles)*(136.1 g/mole) = 198 grams of CaSO4. We actually got 198 grams, so the yield is 100% [Nice work].
Please help serious answers only
Answer:
Uranus
Explanation: Earth's distance from the Sun is about 150 million kilometers. Dividing Earth's distance to sun with the Uranus' distance to the Sun will give us the quotient of 20. Hence, Uranus is the planet that is 20 times farther from the Sun than the Earth is.
why can you find different features at an oceanic-continental convergent zone than those found at a continental-continental convergent zone?
a solution was made by dissolving a salt in water. what is the correct term for the salt when dissolved in water.
a precipitate
b insoluble
c solute
d solvent
Solute
The salt being dissolved is the solute.
Which is the term for a pattern that repeats? A)metal B)metalloid C)noble gas
D)non metal/
What is "a sea of electrons"
Answer:
In metallic bonds, the valence electrons from the s and p orbitals of the interacting metal atoms delocalize. That is to say, instead of orbiting their respective metal atoms, they form a “sea” of electrons that surrounds the positively charged atomic nuclei of the interacting metal ions.
QUICK QUESTION: On the Bohr model, how come potassium has 19 electrons in its valence shell if potassium has a K+? Isn’t it suppose to have 18 electrons? I thought that if an ion has a positive charge, the atom has lost electrons. Pls help me
I WILL GIVE BRAINLIEST TO THE BEST ANSWER
Answer: K only has 1 valence electron. It will leave with only a little effort, leaving behind a positively charged K^+1 atom.
Explanation: A neutral potassium atom has 19 total electrons. But only 1 of them is in potassium's valence shell. Valence shell means the outermost s and p orbitals. Potasium's electron configuration is 1s^2 2s^2 2p^6 3s^2 3p^6 4s^1. The 4s orbital is the only orbital in the 4th energy level. So it has a valency of 1. This means this electron will be the most likely to leave, since it is the lone electron in the oyutermost energy level (4). When that electron leaves, the charge on the atom go up by 1. The atom now has a full valence shell of 3s^2 3p^6, the same as argon, Ar.
Hydrochloric acid reacts with sodium hydroxide according to the equation:
NaOH + HCl 2 NaCl + H2O
25 cm of NaOH was neutralized by 26 25 cm of 0 1 mol/dm HCI
a
Calculate how many moles of HCI was neutralized
b
Calculate how many moles of NaOH was neutralized.
Calculate the concentration of the NaOH used
Answer:
Explanation:
Hydrochloric acid reacts with sodium hydroxide according to the equation:
NaOH + HCl ------> NaCl + H2O
25 cm of NaOH was neutralized by 26. 25 cm^3 of a 0.1 M solution of HCl.
Calculate how many moles of HCI was neutralized
if 1 liter of the HCl has 0.1 moles, 100 ml has 0.01 moles
so 26.25 ml has 0.01 X26.25/100 moles or 0.002625 moles
b
Calculate how many moles of NaOH was neutralized. the reaction is 1:1
so 0.002625 moles of NaOH were reacted.
Calculate the concentration of the NaOH used
25 ml of NaOH were used so the concentration was
(0.002625/25) x 10^3=0.000101X1000 =0.105 MOLES/LITER
how many calories are required to boil 75 grams of water not in sig figs
Well, each ml of water requires one calorie to go up 1 degree Celsius, so this liter of water takes 1000 calories to go up 1 degree Celsius. (There are 1000 ml, each of which needs to have its temperature raised.)
if the reactants of a reaction have ab initial mass of 25 grams what is the mass of the product?
Answer:
It remains the same
Explanation:
The law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. For example, the mass of sodium plus the mass of chlorine that reacts with the sodium equals the mass of the product sodium chloride.
Quiz
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59:52
A scientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide,
oxygen, and nitrogen. Which term most likely describes what she is measuring?
O final pressure
atmospheric pressure
O combined pressure
O partial pressure
Answer:
I'm assuming atmospheric pressure, since it says she is measuring pressure exerted my atmospheric gases
I need help with these questions.
Answer:
descritive advective also know as qualitative
Can stars less massive than our sun produce elements up to iron?
Answer:After the hydrogen in the star's core is exhausted, the star can fuse helium to form progressively heavier elements, carbon and oxygen and so on, until iron and nickel are formed. ... Supernova explosions result when the cores of massive stars have exhausted their fuel supplies and burned everything into iron and nickel.
The heat of solution of KI is 20.3 kJ/mol.
This means that when one mole of KI dissolves in water the process will be
PLEASE EXPLAIN ANSWER
a. Exothermic, ΔH is positive
b. Exothermic, ΔH is negative
c. Endothermic, ΔH is negative
d. Endothermic, ΔH is positive
Since the heat of solution of KI is 20.3 kJ/mol, the answer to the question is a. Exothermic, ΔH is positive
There are two types of chemical reactions namely exothermic and endothermic reaction.
For exothermic reactions, heat is released. So, ΔH is positiveFor endothermic reactions, heat is absorbed. So, ΔH is negativeGiven the heat of solution of KI as 20.3 kJ/mol.
Since it is positive, the reaction is exothermic and ΔH is positive
Since the heat of solution of KI is 20.3 kJ/mol, the answer to the question is a. Exothermic, ΔH is positive
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carbon-carbon covalent bonds, such as the ones in carbohydrates and lipids, are _____ and have _____.
Answer:
Weak; a lot of potential energy.
Explanation:
Carbon-carbon covalent bonds, such as the ones in carbohydrates and lipids, are weak and have potential energy.
What is covalent bond?In chemistry, a covalent bond is a chemical connection between two ions or atoms in which their respective electron pairs are shared. A molecular bond is another name for a covalent link.
Several other chemical species, including radicals and macromolecules, may also include this kind of connection. Irving Langmuir invented the term "covalence" around 1919 to characterize the quantity of electron pairs exchanged by nearby atoms, but the phrase "covalent bond" wasn't used until 1939. Carbon-carbon covalent bonds, such as the ones in carbohydrates and lipids, are weak and have potential energy.
Therefore, carbon-carbon covalent bonds, such as the ones in carbohydrates and lipids, are weak and have potential energy.
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