If there are 50 grams of a radioactive element how much will be present after 1 half life,2,half life, and 3 half life

6.25g

a half life will take away half of the element so you wouldjut divide by 2 three times

Explanation:

1HL- 25g, 2HL- 12.5g, 3HL- 6.25g

Explanation:

When trying to calculate Half Lives (HL) you want to make sure that you divide by 2 every time as a half life cuts the amount in half  so 50/2=25(1HL) 25/2=12.5(2HL) 12.5/2=6.25(3HL) and of course dont forget the unit which is grams

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.