Hey there! Here is the answer:
B.) decrease; increase
Here's why:
As you move from left to right across a period on the periodic table the size of an atom will decrease. As you move from top to bottom down a group on the periodic table the size of an atom will increase.
I really hope this answer helps you out! :)
Answer: (C) conservation of matter
Solution: Law of conservation of matter or mass states that' total mass of the reactants should always be equal to the total mass of the product that is the total mass is remained conserved in a chemical reaction.
A balanced chemical equation always follow this law.
For example:

Mass of hydrogen = 1 g/mol
Mass of Oxygen = 16 g/mol
Total mass on the reactants = 2(2×1)+(2×16)= 36g/mol
Total mass on the product side = 2[(2×1) +16] = 36 g/mol
As,
Mass on reactant side = Mass on the product side
Therefore, a balanced chemical reaction follows Law of Conservation of mass.
Answer:
<em>The electrons in an atom can only occupy certain allowed energy levels to a lower one</em>, the excess energy is emitted as a photon of light, with its wavelength dependent on the change in electron energy. This is why an atom can only emit specific wavelengths of light and not every possible wavelength.
Rutherford's model shows that an atom is mostly empty space, with electrons orbiting a fixed, positively charged nucleus in set, predictable paths. ... It was after this that Rutherford began developing his model of the atom.
Answer:
See below
Explanation:
You missed the following elements, but any element with 7 valence electrons could behave like that: Cl, Br, I, F, etc