Answer:
Moving Across a Period
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons
Bond number
The characteristic of reactions that depends on valence electrons is the bond type.
In chemistry, a chemical bond could be;
Ionic
Covalent
The type of bond formed depends on the number of valence electrons present. When there are few valence electrons on an atom, it mostly forms ionic bonds.
When there are more electrons on an atoms, it mostly forms covalent bonds and the electrons between the atoms are shared.
Answer:
16.06 L was the initial volume of the balloon.
Explanation:
Initial moles of freon in ballon = 
Initial volume of freon gas in ballon = 
Moles of freon gas added in the balloon = n = 3.50 mole
Final moles of freon in ballon = 
Final volume of freon gas in ballon = 
Using Avogadro's law:
( at constant pressure and temperature)

16.06 L was the initial volume of the balloon.
Answer:
Explanation:
Ksp(BaSO4)=1.07×10−10
BaSO₄ → Ba²⁺ + SO₄²⁻
1.07×10⁻¹⁰ = ( Ba²⁺) × ( SO₄²⁻)
but Ba²⁺ = 1.3×10⁻² M
1.07×10⁻¹⁰ = 1.3×10⁻² M × ( SO₄²⁻)
( SO₄²⁻) = 1.07×10⁻¹⁰ / 1.3×10⁻² = 0.823 × 10⁻⁸ M
while Ksp(CaSO4)=7.10×10−5
CaSO₄ → Ca²⁺ + SO₄²⁻
7.10×10⁻⁵ = 2.0×10⁻² × ( SO₄²⁻)
( SO₄²⁻) = 7.10×10⁻⁵ / 2.0×10⁻² = 3.55 × 10⁻³ M
comparing the concentration of sulfate ions, Ba²⁺ cation will precipitate first because the Ba²⁺ requires 0.823 × 10⁻⁸ M sodium sulfate which less compared the about needed by CaSO₄