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Dahasolnce [82]
4 years ago
9

Which sample contains a total of 3.0 x 10^23 molecules?

Chemistry
1 answer:
belka [17]4 years ago
3 0
Given that 1 mole contains 6.02x10^23 molecules, 3.0x10^23 is just around half a mole. Then we check the number of moles for each choice:

A. This is approximately half a mole, since the molar mass of Br2 is 159.8 g/mol.
B. He has a molar mass around 4 g/mol, so this is 1 mole.
C. H2 has a molar mass of 2.02 g/mol, so this is 2 moles.
D. Li has a molar mass of around 6.97 g/mol, so this is around 2 moles.

Therefore the only choice that fits is A. 80 g of Br2.
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Urgent help needed please!Write the electron configuration for vanadium. (Use superscript and proper formatting for full credit.
alexandr402 [8]

Answer:

Ar 3d3 4s2 is the electron configuration for Vanadium.

4 0
3 years ago
How can you write noncontact force in a sentence
Kaylis [27]
Here Is A Sentence You Could Possibly Use:

"The most common usage of non-contact force is weight."

Hope This Helps!

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5 0
3 years ago
If the forces acting on an object are unbalanced, what will occur?
S_A_V [24]

Answer:

The answer is acceleration.

Explanation:

Acceleration- When it comes to science, Force is defined as a "push or pull" of an object with mass that causes it to change velocity.

Balanced Force- This occurs when two forces of the same mass or size are acting on a particular object in opposite direction. The object being acted upon could <em>either stay in its place or move in a uniform speed and direction.</em>

Unbalanced Force- This occurs when the forces applied are not equal and are of different direction. For example, a 55-kg person pulling a 30-kg cart. The cart will move to the direction of the pull.

Thus, when forces acting on an object are unbalanced, it causes the object to accelerate. This acceleration is directly proportional to the "net force", but is inversely proportional to the mass or size.

<u>A net force</u> is the total amount of force that is acting on the object.

6 0
3 years ago
________ is defined as the number of protons plus the number of neutrons. ________ is defined as the number of protons plus the
velikii [3]

Answer:

Mass number is defined as the number of protons plus the number of neutrons.

Explanation:

Every atom of an element have proton(s), neutron(s) and electron(s). The proton number of an element is the atomic number of that element. For an electronically neutral atom the proton number is equal to the electron numbers. The neutron and the proton contributes to the mass of every atom. The electron is more active when atoms are bonding.

Mass number of an element is the number of proton plus the number of neutron.  

Atomic number of an atom is the number of proton present, so it can never be atomic number.

Isotopy talks about same element having different number of neutron but same number of protons in each atom.  Example is hydrogen that exist as protium, deuterium and tritium. It cannot be isotopic number.

Ionic number talks about elements that possess a charge. The elements have been ionized.

The answer is Mass number because the sum of proton number and neutron number is equals to mass number.

4 0
3 years ago
The amount of heat (q) gained or lost by a substance (with mass m) as its temperature changes (ΔT) depends on its specific heat
wariber [46]

Answer:

As the specific heat capacity for pure diamond is 0.5091\frac{J}{g.K} and it is different from the specific heat capacity found that is 0.2699\frac{J}{g.K}, the diamond sample is not pure.

Explanation:

1. As the problem says the equation that describes the amount of heat gained or lost by a substance is:

q=Cp*m*(T_{2}-T_{1})

q=Cp*m*ΔT

where q is the amount of heat, Cp is the specific heat capacity, m is the mass and ΔT is the change in the temperature.

2. Solving for specific heat capacity:

Cp=\frac{q}{m*(T_{2}-T_{1})}

3. Replacing values:

Cp=\frac{26.21J}{2.03g*(73.81C-25.99C}

Cp=0.2699\frac{J}{g.K}

As the specific heat capacity for pure diamond is 0.5091\frac{J}{g.K} and it is different from the specific heat capacity found that is 0.2699\frac{J}{g.K}, the diamond sample is not pure.

3 0
3 years ago
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