What is the average atomic mass of Si if 92.21% of its atoms have mass 28 amu, 4.70% of its atoms have mass 29 amu, and 3.09% of its atoms have mass 30
amu?

Which of the following best describes the formation of plasma?

The diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

According to coulomb's law, how would the electrical force between particles change if the product of their electrical charge increased?