Answer:
The example of reflection of light is surface of smooth pool of water and the example of reflection of sound is echo.
The outer planets of the solar system that are known as Gas Giants
The answer is the atomic mass.
<h2>Answer:</h2>
What does Atomic number represents ___________.
What does the Mass number represent ___________
Periods are _____________ rows.
Groups are _____________ columns.
Total elements in periodic table are _____________.
1 half-life - 4.5 days
x half-lives - 27 days
x=(1*27)/4.5=6
6 <span>half-lives have elapsed after 27 days.</span>
