What do you predict the trend in atomic mass will be going down a group?

The trend that is observed is that the atomic radii decrease going across a period. Atomic radii increase going down a group.

The trend in atomic mass going down a group is an increase in atomic mass. This is because additional energy levels (shells) and electrons and protons are being added as one moves down a group.

The atomic mass will increase. As you go down a group in the periodic table the atomic number rises, this increase in the number of protons is accompanied by an increase in the number of neutrons to stabilise the nucleus, and both together lead to an increase in atomic mass.

The atomic radius increases as we go down the group as the number of shell increases down the group.

The atomic radius of elements in a group increases with the atomic number.

Answering "What is the trend in variation of atomic size of elements across the period and down the group?"

As you move from left to right across a period, the atomic mass of the elements will increase.

the atomic radii increases down the group.

Atomic radius increases down the group. This is because of the increase in number of shells.

the atomic radius increases

Down a group, the energy level (or shells) increases, and hence generally atomic radius (size) increases.

Atomic radius increases down a group.

Among all the main groups the trend of increasing atomic size down the group is observed.This is because of addition of extra shell as we move down the group.

Trend is something happening like vine is a trend right now and prediction is something you think is going to happen like a predict vine is still going to be popular in a year

Atomic radius increases down the group