2.0 g 1.0g 0.5g 0.25g
3 and a half lives = 42 days
<u>Answer:</u> Electrons are taken up by
and they are lost by 
<u>Explanation:</u>
Redox reaction is defined as the reaction in which oxidation and reduction take place simultaneously. It is also called the reaction where the exchange of electrons takes place.
An oxidation reaction is defined as the reaction in which a chemical species loses electrons takes place. In this reaction, the oxidation state of a substance gets increased.
A reduction reaction is defined as the reaction in which a chemical species gains electrons takes place. In this reaction, the oxidation state of a substance gets reduced.
For the given chemical reaction:

The half-reactions for this redox rection follows:
<u>Oxidation half-reaction:</u> 
<u>Reduction half-reaction:</u> 
Hence, electrons are taken up by
and they are lost by 
The answer is <span>D.when the aim is to show electron distributions in shells. This is because there are some instances when elements don't possess a regular or normal electron configuration. There are those who have special electron configurations wherein a lower subshell isn't completely filled before occupying a higher subshell. It is best to visualize such cases using the orbital notation.</span>
Answer:
The correct answer is 24.31 amu.
Explanation:
The formula for finding the average atomic mass = The sum of the percentage abundance of isotopes × the actual mass of isotopes
The average atomic mass = % abundance of Mg-24 × actual mass + % abundance of Mg-25 × its actual mass + % abundance of Mg-26 × its actual mass
Avg. Atomic mass = 0.7870 × 23.98504 + 0.1013 × 24.98584 + 0.1117 × 25.98259
Avg. atomic mass = 18.88 + 2.53 + 2.90 = 24.31 amu
The atomic mass of magnesium is 24.31 amu.