Hlepthe half-life of cobalt-60 is 5.26 years. after 10.52 years, 5 grams of a 20-gram sample will remain.

select one:

true

false

The half-life of cobalt-60 is 5.26 years. After 10.52 years, 5 grams of a 20-gram sample will remain is TRUE

Explanation:

Mass of cobalt = 20 g  

Half-life = 5.26 years  

Mass remains after 10.52 years = 5 g  

This can be solved by using given below formula,

= initial mass  

t = number of years from when the mass was m_0  

m(t) = remaining mass after t years  

Number of half-lives =

Number of half-lives =

Number of half-lives = 2  

At time zero = 20 g  

At first half-life =  = 10 g  

At second half life = = 5 g  

The given statement is true.

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.