All are gases so no visible reaction persay, unless in closed quarters and then massive pressure.
The answer to the question is radium (Ra)
Answer:
22:
Formular:

substitute:

23:
<em>Same</em><em> </em><em>element</em><em> </em><em>is</em><em> </em><em>represented</em><em> </em><em>by</em><em> </em><em>same</em><em> </em><em>number</em><em> </em><em>of</em><em> </em><em>protons</em><em>.</em><em> </em>
Answer:
6 protons. 6 protons
7 neutrons. 8 neutrons
6 electrons. 6 electrons
Note: <u>Atoms</u><u> </u><u>with</u><u> </u><u>same</u><u> </u><u>proton</u><u> </u><u>number</u><u> </u><u>but</u><u> </u><u>different</u><u> </u><u>mass</u><u> </u><u>number</u><u> </u><u>are</u><u> </u><u>called</u><u> </u><u>isotopes</u>
Answer:
Iron remains = 17.49 mg
Explanation:
Half life of iron -55 = 2.737 years (Source)
Where, k is rate constant
So,
The rate constant, k = 0.2533 year⁻¹
Time = 2.41 years
= 32.2 mg
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
So,
<u>Iron remains = 17.49 mg</u>