Answer:
The answer is
<h2>11.25 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula

From the question
mass = 45 g
volume = 4 mL
Substitute the values into the above formula and solve for the density
We have

We have the final answer as
<h3>11.25 g/mL</h3>
Hope this helps you
Answer:
A) (3.2g)
Explanation:
Did you reposed this? Because I remember answering this
Answer:
Chemical change :has change in mass, heat is needed, new element is formed, hard to reverse.......
Physicalchange:does not have change in mass, heat is not necessary, no new element is formed, easy to reverse
We use the following formula to calculate the number of atoms:
n (mol) = N(number of atoms) / NA
N(He) = n(mol) · NA
N(He) = 2,0 moles · 6.02·1023 = 12.04·1023 atoms