The answer is 1/16.
Half-life is the time required for the amount of a sample to half its value.
To calculate this, we will use the following formulas:
1.

,
where:
<span>n - a number of half-lives
</span>x - a remained fraction of a sample
2.

where:
<span>

- half-life
</span>t - <span>total time elapsed
</span><span>n - a number of half-lives
</span>
So, we know:
t = 10 min
<span>

= 2.5 min
We need:
n = ?
x = ?
</span>
We could first use the second equation to calculate n:
<span>If:

,
</span>Then:

⇒

⇒

<span>
</span>
Now we can use the first equation to calculate the remained fraction of the sample.
<span>

</span>⇒

<span>⇒

</span>
G'day love! An elements atomic number is the amount of protons in an element!
Answer:
c The concentration(s) of reactant(s) is constant over time.
Step-by-step explanation:
When the reaction A ⇌ B reaches equilibrium, the concentrations of reactants and products are constant over time.
a is <em>wrong</em>, because the concentrations of reactants and products are usually quite different.
b is <em>wrong</em>, because both product and reactant molecules are being formed at equilibrium.
d is <em>wrong</em>. The rates of the forward and reverse reactions are equal, but they are not zero.
Answer:
False
That is a chemical change