How do i determine the number of silicon atoms in the formula 4SiO2

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

An animal cell loses the ability to convert energy stored in food to energy that the cell can use. which of the cell's organelles has stopped working? a.the mitochondria b.the nucleus c.the vacuoles d.the endoplasmic reticulum

Why does asexual reproduction result in offspring with identicle genetic variation