What mass of water (H2O)will be collected if 20.0 grams of oxygen gas(H2) are consumed
2H2+O2-->2H2O

Explanation:

no.mole of H2= mass/RAM

=20/2(2)

=5mol

no.mole of H20=mass/RAM

=5molx2(2+16)mol/g

=180g

c is the answer because when something is left after something evaporates that shows the chemical change.

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.