How does the atomic radius change as you go from left to right in a period?

How would the tendency to gain electrons change as you go from left to right across a period?

what happenes to metallic character as we move from left to right across a period

How does the valency vary in going down a group?

How does the density of a body change with temperature ?

How does the apical meristem differ from lateral meristem?

In the transition series with an increase in atomic number the atomic radius does not change very much. Why is it so?