more reactive metals:
potassium (highest reactivity)
sodium
calcium
magnesium
moderate reactive metals:
aluminium
zinc
iron
lead
least reactive metals:
copper
mercury
silver
gold (least reactivity)
It need "3 electrons" to have a stable electronic configuration.
'cause it has 5 electrons in it's outer shell & every atom needs 8 electrons. So, it requires 3 more!
Hope this helps!
If the two gases has a total pressure of 5.7 atm and one of the gases has a partial pressure of 4.1 the the other one has the pressure of 1.6