I believe the answer is carbon atoms
Answer: It is true that Your friend should release the 
first.
Explanation:
The velocity of particles of a gas is inversely proportional to the mass of gas. This means that more is the mass of gas less will be its velocity.
Or, more will be the mass of gas more slowly it will move from one place to another.
The molar mass of chlorine gas is more than the molar mass of hydrogen gas. Therefore, chlorine gas will move slowly.
So, your friend should release the gas first and then according to the length of room you should release the 
gas.
Thus, we can conclude that it is true that Your friend should release the first.
Answer:
0.712 mol
Explanation:
The easiest way to do this is to use a proportion.
1 mol of copper = 63.5 grams (check this using your periodic table).
x mol of copper = 45.2 grams
1/x = 63.5 / 45.2 Cross multiply
63.5 x = 1 * 45.2 Divide by 63.5
x = 45.2/63.5
x = 0.712 mol Answer to 3 sig digs
The mass defect for the isotope thorium-234 if given mass is 234.04360 amu is 1.85864 amu.
<h3>How do we calculate atomic mass?</h3>
Atomic mass (A) of any atom will be calculated as:
A = mass of protons + mass of neutrons
In the Thorium-234:
Number of protons = 90
Number of neutrons = 144
Mass of one proton = 1.00728 amu
Mass of one neutron = 1.00866 amu
Mass of thorium-234 = 90(1.00728) + 144(1.00866)
Mass of thorium-234 = 90.6552 + 145.24704 = 235.90224 amu
Given mass of thorium-234 = 234.04360 amu
Mass defect = 235.90224 - 234.04360 = 1.85864 amu
Hence required value is 1.85864 amu.
To know more about Atomic mass (A), visit the below link:
brainly.com/question/801533
The periodic table is one of the most important tools in the history of chemistry. It describes the atomic properties of every known chemical element in a concise format, including the atomic number, atomic mass and relationships between the elements. Elements with similar chemical properties are arranged in columns in the periodic table.
The table thus is a quick reference as to what elements may behave the same chemically or which may have similar weights or atomic structures.
Hope this answer helps you
