Vesna drew a diagram of earths tilt on its axis. what angle should vesna

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

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?

Can someone me with questions 12 and 13 plz.