Answer:
D
Explanation:
Just look at the groups and their tendencies. Or look at their electron configurations. You will notice that calcium has 2 valence electrons and bromine has 7 valence electrons.
Halogens have the most valence electrons possible without completing a shell (8 would be needed for that)
Mass number is the sum of protons and neutrons inside an atom.
Atomic mass = no. of protons + no. of neutrons
PH scale is used to determine how acidic, basic or neutral a solution is
pH can be calculated using the H₃O⁺
ph can be calculated as follows
pH = - log[ H₃O⁺]
[H₃O⁺] = 1 x 10⁻⁹
pH = - log [1 x 10⁻⁹]
pH = 9
pH of solution is 9
Lewis diagram:
well first you have to know the Valence electrons the elements which will on top of the periodic table.
for examples:
H2O
it will be O-H-O and the dots will on top. oxygen have 6 valence electrons so that mean it need 6 dots. also for H it will have 7 V-electrons.
