Because of hydrogen bonding, select one: a. lakes freeze from the bottom up b. ice is less dense than liquid water c. ice sinks to the bottom of water d. liquid water is less dense than ice

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?

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

Classify this reaction: 2al+n2-> aln.