Answer:
Across a row, atomic radii decreases.
Explanation:
It decreases because nuclear charge increases across a row, electrons are added to the same shell and shielding remains constant. Therefore the outer electrons are more attracted to the nucleus making the atom smaller.
True
D
From periodic table : proton number 19 corresponds to K (potassium)
which is very reactive with water
the
first one
4.4g
Mass of CaCO3 = 10g
Mass of CaO = 5.6g
Mass of CO2 =?
Mass of CaCO3 = Mass of CaO + Mass of CO2
Mass of CO2 = Mass of CaCO3 — Mass of CaO
Mass of CO2 = 10 — 5.6
Mass of CO2 = 4.4g
