Cause he left out the noble gases out of the periodic table for one good reason, 1: He did not know them
Molecular mass may be calculated by taking the atomic mass of each element present and multiplying it by the number of atoms of that element in the molecular formula. Then, the number of atoms of each element is added together. This value may be reported as a decimal number or as 16.043 Da or 16.043 amu.
Answer:

Explanation:
From frequency of oscillation

Initially with the suspended string, the above equation is correct for the relation, hence

where k is force constant and m is the mass
When the spring is cut into half, by physics, the force constant will be doubled as they are inversely proportional

Employing f2/ f1, we have

Answer:
Because each color is refracted differently, each bends at a different angle, resulting in a fanning out and separation of white light into the colors of the spectrum.
There are 2 elements:
Beryllium ( Be + 2 ), metal
Bromine ( Br - 1 ), non - metal
They form the ionic bond:
Be + Br2 → Be Br2
Naming the ionic compound:
on the 1st place is metal. On the 2nd place is non-metal. If compound is binary, use the element name and change ending to - ide .
Answer:
Beryllium Bromide.