7 days = 1 week 60 seconds<span> = 1 minute.</span>
40 hr 60<span> min </span>60 sec<span> = </span>144,000<span> s.
The answer is 144,000 seconds hopes this helps :)</span>
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
<u>Explanation:</u>
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.
The answer is 2 electrons I believe!
Correct Question:
A spectator ion is (Select all that apply.)
- a piece of french fry contaminating the reaction mixture
- an ionic component of a reactant that is unchanged by the reaction
-in this experiment, nitrate ion
- your eye, carefully watching the progress of the reaction
Answer:
- an ionic component of a reactant that is unchanged by the reaction
Explanation:
A spectator ion is an ion that exists as a reactant and a product in a chemical equation. A spectator ion is one that exists in the same form on both the reactant and product sides of a chemical reaction.
Spectator ions are ions that are present in a solution but don't take part in the reaction. When reactants dissociate into ions, some of the ions may combine to form a new compound. The other ions don't take part in this chemical reaction and are therefore called spectator ions.
The correct option is therefore the option;
- an ionic component of a reactant that is unchanged by the reaction
