Which of the following is true about Earth's supplies of freshwater? a. Most liquid freshwater is stored in rivers and lakes.
b. Groundwater is a significant reservoir of liquid freshwater.
c. Liquid freshwater is about half of all the water on Earth.
d. None of the above.

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Why does his teacher ask him to balance the equation by including the correct coefficient

In the reaction between a crushed antacid tablet and vinegar what gas is emitted