Biology ! ( 40 pts ) and you!

which of the following elements would be the most reactive?

strontium
nitrogen
chlorine
radon

name an element which will chemically behave like xenon.

iodine
carbon
neon
plutonium

how many electrons does a neutral atom of calcium (ca) possess?

none
five
twenty
fourty

what are the starting chemicals in a reaction called?

the products
the reactants
the equilibrium
the yield

what would be a representation of a single-replacement reaction?

a + b --> ab
ab --> a + b
ab + c --> ac + b
ab + cd --> ad + cb