Answer:
Explanation:
Antibiotics are chemical agents that are used to treat bacterial infections. ... Vaccines are used to prevent infection, particularly viral infections.
The answer is 1/8.
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>
The half-life of Sr-90 is 28.8 years.
So, we know:
t = 87.3 years
<span>

= 28.8 years
We need:
n = ?
x = ?
</span>
We could first use the second equation, to calculate n:
<span>If:

,
</span>Then:

⇒

⇒

<span>⇒ n ≈ 3
</span>
Now we can use the first equation to calculate the remained amount of the sample.
<span>

</span>⇒

⇒

<span>
</span>
Answer:
Red pandas live in the Eastern Himalayas in places like China, Nepal, and Bhutan . They spend most of their time in trees. Their semi-retractable claws help them move easily from branch to branch.
Explanation:
my answer would be A
Answer:
1.Physical. People measure water by themselves.
2.Physical. People chop wood.
Explanation:
(this is all I can answer for you. you have to explain it by yourself tho.)
I dont know if I'm correct so you should double check.
D is the answer its Atoms are mostly empty space with small, dense, positively charged centers.