Answer:
H₂
Explanation:
To solve this question we must find, as first, find the molar mass of the homonuclear diatomic gas using Graham's law. With the molar mass we can identify this gas
<em>Graham's law:</em>

<em>Where V is the speed of the gases and m the molar mass of those:</em>
<em>As Va is 3.98 times Vb (And mB is molar mass of oxygen gas = 32g/mol)</em>

15.84 = 32g/mol / mA
mA = 2.02g/mol
As is a homonuclear diatomic gas, the molar mass of the atom is 1.01g/mol. Thus, the gas is:
<h3>H₂</h3>
The answer is C) catalyst speed up reactions and activation energy
Electronegativity refers to the ability of an atom to attract shared electrons in a covalent bond. The higher the value of the electronegativity, the more strongly that element attracts the shared electrons.
<u>Answer:</u>
17%
<u>Explanation:</u>
Mass of a piece of copper calculated by student = 8.3 grams
Actual mass of copper = 10 grams
We know the formula for the percent error:
Percentage error = (| experimental value - actual value | / actual value) * 100
So substituting the given values in the above formula:
Percent error = (|8.3 - 10| / 10) * 100 = (1.7/10) * 100 = 17%
Answer: your question is easy 21 L