What are the trends in group 1 and group 7?

group one get more reactive as they go down because of added shielding and gravitational force. They are further away from the positive nucleus and so it is easier for them to loose the outer electron. They get bigger as they go down because with each period you go down there is a full electron shell (energy level) In group 7 there is a negative effect of this. Although the mass trend is the same (ie they get heavier) they are less reactive as they go down for the same reason that group 1 is more reactive. They want to attract an electron to fill their energy level and so, being closer to the nucleus increases gravitational force.