Answer:
earth
Explanation:
water vapor, water, ice
How many moles are in 25.5g of helium?
1) A box has a mass of 8 kg and a volume of 2 m? What is its density? |
[tex]\huge\boxed{4\ \text{kg/m$^3$}}[/tex]
We know that [tex]\rho=m\div V[/tex], where [tex]\rho[/tex] is density, [tex]m[/tex] is mass, and [tex]V[/tex] is volume.
Substitute in the values we know and solve:
[tex]\begin{aligned}\rho&=8\div2\\&=\boxed{4}\end{aligned}[/tex]
In the Ames Test, the appearance of his revertants in the presence of a non-mutagenic control compound indicates that _______.
Answer & Explanation: The Ames test examines the mutagenic effects of chemicals ; as such, it detects whether a given chemical can cause a reversion mutation in his- bacteria. While this is the purpose of the test, some of the reversion mutations are not caused by the mutagen being tested for. The appearance of his revertants in the presence of a non-mutagenic control compound therefore indicates that His+ revertants on the control plate are the result of spontaneous mutation.
Trimethylamine, (CH3)3N is a weak base (Kb = 6.3 × 10–5). What volume of this gas, measured at STP, must be dissolved in 2.5 Lof solution to give that solution a pOH of 2.50?
Answer:
8.9L is the volume of the gas that must be dissolved.
Explanation:
For a weak base, we can find [(CH₃)₃N] using the equation:
Kb = [OH⁻] [[(CH₃)₃NH⁺] / [(CH₃)₃N]
As [OH⁻] = [[(CH₃)₃NH⁺] and [OH⁻] = 10^-pOH = 3.16x10⁻³M:
6.3x10⁻⁵ = [3.16x10⁻³M][3.16x10⁻³M] / [(CH₃)₃N]
[(CH₃)₃N] = 0.1587M
As the volume is 2.5L, moles are:
2.5L * (0.1587mol / L) = 0.3968moles
Using:
PV = nRT
We can solve for volume of the gas as follows:
P = 1atm at STP; n = 0.3968moles; R = 0.082atmL/molK; T = 273.15K at STP
V = 0.3968mol*0.082atmL/molK*273.15K/1atm
V = 8.9L is the volume of the gas that must be dissolved.
what atoms do we call radioactive isotopes?
Answer:
Radioisotopes are radioactive isotopes of an element. They can also be defined as atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus.
Explanation:
carbon paired electrons
Answer:
what about carbon paired electrons? what do you need to know about them?
Explanation:
Science and technology affect people's behaviors. Which of the following is NOT a way in which science and technology have affected someone's behavior or choices?
A.
Many people use hand sanitizer.
B.
A college student decides to study all night.
C.
A family cuts down on how much saturated fat they consume.
D.
A local contractor decides to install only water-efficient toilets.
What change would most likely decrease the rate of a chemical reaction? A) maintaining a temperature close to room temperature B) decreasing the volume of the container C) heating of the reaction mixture D) cooling of the reaction mixture
Answer:
D) cooling of the reaction mixture
Explanation:
Increase in temperature speedens the rate of a chemical reaction
How do I memorize all the elements on the periodic table?
Answer:
write down each element and what you need to know about it repeatedly, and it will burn into your brain
Explanation:
Which of the following is not a property of nonmetals?
excellent electrical conductor
semiconductor
found on the right side of the periodic table
solids tend to be dull and brittle
Answer:
Excellent Electrical Conductors.
Explanation:
(Though I believe some of these answers could be worded better), Most non-metals are terrible conductors of electricity and heat. Nonmetals in solid forms lack luster and can be brittle, and there are semiconductors compared to Metals.
Answer:
Excellent Electrical Conductor, I believe.
Explanation:
Most metals are good electric conductors...
Id wait until somebody else answers to verify my answer.
The Fahrenheit scale is most commonly used _____.
A.inside European countries
B.inside the United States
C.in studies of other planets
Answer:
B The United States
Explanation:
most other countries use the C to measure their temperature
Write the isotope notation for an element with 53 protons and 20 neutron?
The isotope notation : ⁷³₅₃X
Further explanationGiven
53 protons and 20 neutron
Required
The isotope notation
Solution
Isotopes are elements that have the same atomic number with a different mass number
The following element notation,
[tex]\large {{{A} \atop {Z}} \right X}[/tex]
X = symbol of element
A = mass number
= number of protons + number of neutrons
Z = atomic number
= number of protons = number of electrons, on neutral elements
So the mass number of element = 53 + 20 = 73
Atomic number = 53
The symbol :
[tex]\large {{{73} \atop {53}} \right X}[/tex]
1. Which is a property of most molecular compounds?
Answer: Low melting points
Explanation:
What is the product of the unbalanced combustion reaction below?
CH2(g) + O2(g) →
A. C(s) + H2(g) + O2(g)
B. C(s) + H20(g)
C. CO2(g) + H20(g)
D. CH2O(s)
i think its the answer D
What is the acceleration of a 5 kg object if a force of 50 N was applied to it?
a
45 m/s2
b
250 m/s2
c
10 m/s2
d
55 m/s2
Answer:
c.10 m/s²
Explanation:
By the newton's second law
Question 1.
Which is a limitation of using cellulose?
A.its lack of mass production
B.its lack of biodegradability
C.its harm to landfills
D.its high cost to recycle
Question 2.
Which refers to a macromolecule that forms as a result of the joining of multiple monomers?
A. amino acid
B. glucose
C. nucleic acid
D. polymer
Question 3
What does the octet rule state that explains why atoms bond?
A. Atom bonds have eight valence electrons to become stable.
B. Atom bonds lose eight valence electrons to become stable.
C. Atom bonds have eight valence electrons to become unstable.
D. Atom bonds to lose eight valence electrons to become unstable.
Question 4
Shameeka is studying for an exam. She took the notes below about calcium and chlorine, which are known to form ionic bonds.
Calcium, which is a metal, donates 2 electrons to chlorine.
The individual calcium atoms become ions with a negative 2 charge.
The bond between calcium and chlorine makes the atoms stable.
Calcium and chlorine attract each other.
Which best describes Shameeka’s error?
A.Calcium is a metal, so it donates protons, not electrons.
B.The individual calcium atom has a positive, not negative, 2 charge.
C.The bond formed makes the atoms unstable, not stable.
D.Calcium and chlorine repel, not attract, each other.
Explanation:
Question 1
D
Question 2
D
How many protons does an atom with an atomic number of 12 and a mass number of 26 have?
Answer:
12 cuz the atomic number is 12
Explanation:
What are 3 different units of measurement for measuring the amount of space a sample of matter occupies?
Answer:
Liters
Cubic centimeter
Cubic decimeter
Explanation:
The amount of space a matter occupies is the volume of the body. Gases takes up by far the largest amount of space because they fill into any available space.
There are several units of measuring volume but the more common one are:
Liters, Cubic decimeter and cubic centimeter.
The volume of a body can be derived in many ways. Some by measuring and others by indirect quantification.
7. I have 2.50 x 1023 atoms of titanium. How many moles of titanium dol
have?
Answer:
0.42mole
Explanation:
Given parameters:
Number of atoms of titanium = 2.5 x 10²³atoms
Unknown:
Number of moles = ?
Solution:
To solve this problem, we must understand that a mole of any substance contains the Avogadro's number of particles.
6.02 x 10²³ atoms makes up 1 mole of an atom
2.5 x 10²³ atoms will contain [tex]\frac{2.5 x 10^{23} }{6.02 x 10^{23} }[/tex] = 0.42mole
Can somebody plz help answer these true or false questions correctly thanks! (Only if u for sure know them) :)
WILL MARK BRAINLIEST WHOEVER ANSERS THEM FIRST !!!:DDD
Answer:
1. False
2. True
3. False
4. True
5. True
Explanation:
imagine you put a balloon on a bottle full of air, then set the bottle into hot water. The balloon would inflate. why?
What is true of a Lewis acid?
O A. A Lewis acid accepts electron pairs.
O B. A Lewis acid donates H+ ions.
O C. A Lewis acid accepts H+ ions.
O D. A Lewis acid donates electron pairs.
Answer:
a lewis acid accepts electron pairs
Explanation:
a p e x
The fact that is true about Lewis acid is that A Lewis acid donates electron pairs. Hence option D is correct.
What is a Lewis acid?In chemistry, a Lewis acid is a chemical species that can accept a pair of electrons from another species, known as a Lewis base. Lewis acids are electron pair acceptors.
They can be identified by their tendency to form a covalent bond with a Lewis base by accepting a pair of electrons. This definition of Lewis acids and bases, provided by Gilbert N. Lewis, helped to provide a more comprehensive understanding of chemical reactions beyond the traditional acid-base theory.
Common examples of Lewis acids include metal cations, such as aluminum and boron, and compounds such as carbonyl compounds and acids with a positive charge. Lewis acids play an important role in many chemical reactions, including organic synthesis, coordination chemistry, and acid-catalyzed reactions.
Therefore, option D, A Lewis acid donates electron pairs is correct.
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During a demonstration, a teacher makes a mixture by combining 40mL of methanol and 60mL of water, as shown. The teacher asks students to describe what happens so that they can create a model together
Answer:
Explanation:
The solution is a dilute solution of methanol. It is described as a "40% methanol" concentration which means the solution is 40% of methanol in the solution. In this solution, it is 40% of methanol and 60% of water. If any solution is to be prepared from this model, the solution must have 40% of methanol, hence to prepare a 200 mL of the same model (40%) of methanol solution, the volume of methanol would be 80 mL and the volume of water would be 120 mL.
Which characteristics describe most nonmetals in the solid phase?
1
They are malleable and have metallic luster.
2
They are malleable and lack metallic luster.
3
They are brittle and have metallic luster.
4
They are brittle and lack metallic luster.
Answer:
4
Explanation:
its a non-metal, dont get confused and pick number 1- it may seem like that’s the answer but remember here we are talking abut the solid phase!
Periodic table is divided into three metals, non metals and metalloids. The non metals are kept on the right side of the periodic table. Th correct option is option D.
What are non metals?Non metals are the element that have property to gain electron. When any element gain electron then element attain negative charge and that element is called anion. The examples of non metals are Oxygen, nitrogen, carbon, Fluorine etc.
The properties of non metals are
Non metals are soft.
Non metals are not malleable that is they can be broken into thin sheets.
Non metals are not ductile they can not be broken into thin wires.
Non metals are brittle in nature that is they can be broken down easily.
Non metals are not lustrous.
Therefore the correct option is option D.
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What is the best statement about the data collected in Amir’s table?
A. Wave 3 resulted from destructive interference, and Wave 4 resulted from constructive interference.
B. Waves 3 and 4 resulted from constructive interference.
C. Waves 3 and 4 resulted from destructive interference.
D. Wave 3 resulted from constructive interference, and Wave 4 resulted from destructive interference.
Answer: The answer is D :)
Explanation:
Answer:
D
Explanation:
PLEASE HELP ASAP DUE SOON !
Answer:
Physical properties such as size, shape, color, density, magnetism or the ability to sink or float can be used to separate the substances in a mixture.. Filtration is when matter is passed through a filter and the larger particles are separated out.
Explanation:
Given the balanced equation representing a reaction:
Zn(s) + 2HCl(aq) - H2(g) + ZnCl2(aq)
Which set of reaction conditions produces H2(g) at the fastest rate?
A.
a 1.0-g lump of Zn(s) in 50. mL of 0.5 M HCl(aq) at 20.°C
B.
a 1.0-g lump of Zn(s) in 50. mL of 0.5 M HCl(aq) at 30.°C
C.
1.0 g of powdered Zn(s) in 50. mL of 1.0 M HCl(aq) at 20. °C
D
1.0 g of powdered Zn(s) in 50. mL of 1.0 M HCl(aq) at 30.°C
Answer:
D 1.0 g of powdered Zn(s) in 50. mL of 1.0 M HCl(aq) at 30.°C
Explanation:
There are several factors affecting and controlling the rate of chemical reactions.
Some of which are applicable in resolving this problem is the nature of the reactants and their concentration. Also, the temperature of the reaction is also very important.
Reactants that powdered ensures a faster rate because, more surface area is exposed for the reaction. Also, the higher the temperature, the faster the reaction will take place. So, the powdered zinc and the higher temperature reaction will facilitate a better rate of reaction.Help please chapter 7.1
QUICKKKKKK I WILL GIVE BRAINLIEST
When a small volume of water is boiled, a large volume of steam is produced. Why?
Water molecules repel each other when heated.
Water molecules repel each other when heated.
The size of the water molecules increases when heated.
The size of the water molecules increases when heated.
The molecules are further apart in steam than in water.
The molecules are further apart in steam than in water.
The change from water to steam causes the number of molecules to increase.
Answer:
C
Explanation:
The molecules are farther apart in steam than in water.
Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula.
Answer:
the empirical formula is [tex]H_2NO_2[/tex]
Explanation:
The empirical formula is
The following information is given
It contains 29.17 mass percentage of N
4.20 mass percentage of H
And, 66.63 mass percentage of 0
Now based on the above information, the empirical formula is [tex]H_2NO_2[/tex]
hence, the same is to be considered and relevant too
Considering the definition of empirical formula, the empirical formula is H₂N₁O₂= H₂NO₂
The empirical formula is the simplest expression to represent a chemical compound, which indicates the elements that are present and the minimum proportion in whole numbers that exist between its atoms, that is, the subscripts of chemical formulas are reduced to the most integers small as possible.
Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O.
Assuming a 100 grams sample, the percentages match the grams in the sample. So you have 29.17 grams of N, 4.20 grams of H and 66.63 grams of O.
Then it is possible to calculate the number of moles of each atom in the molecule, taking into account the corresponding molar mass:
N:[tex]\frac{29.17 grams}{14 \frac{grams}{mole} }[/tex]= 2.08 molesH:[tex]\frac{4.20 grams}{1 \frac{grams}{mole} }[/tex]= 4.20 molesO:[tex]\frac{66.63 grams}{16 \frac{grams}{mole} }[/tex]= 4.16 molesThe empirical formula must be expressed using whole number relationships, for this the numbers of moles are divided by the smallest result of those obtained. In this case:
N:[tex]\frac{2.08 moles}{2.08 moles}[/tex]= 1H:[tex]\frac{4.20 moles}{2.08 moles}[/tex]= 2.02 ≅ 2O:[tex]\frac{4.16 moles}{2.08 moles}[/tex]= 2Therefore the H: N: O mole ratio is 2: 1: 2
Finally, the empirical formula is H₂N₁O₂= H₂NO₂
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