Large tides, called spring tides, are experienced in the earth's oceans when the moon is in position
a) a.
b) b.
c) a and c.
d) b and d.

Ionic compounds are made of ions, and yet the overall charge of an ionic compound is neutral. why?

Explain which group an element with the electron configuration 1s2 2s2 2p6 3s2 3p6 3d1 4s2 belongs to.

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space