There are 3,500 milliseconds in 3.5 seconds. Hope this helps!
Answer:
The half-life of Material 1 and Material 2 are equal.
step by step explanation;
Material 1 disintegrates to half its mass three times in 21.6 s, to go from 100g
to 12.5g. That is,
100g - 50g - 25g - 12.5g
Material 2 disintegrates to half its mass three times in 21.6 s, to go from 200g to 25g. That is,
200g - 50g - 25g - 12.5g.
This means that regardless of their initial masses involved, material 1 and material 2 have equal half-life.
Their half-life is 21.6 ÷ 3 = 7.2 sec
The answer is (3) CH3COOH. CH3COOH is a acid. It can ionized in water. So the solution can conduct an electric current. And the other three can not be ionized in water.
