Answer is: <span>an atomic radius.
</span>The atomic radius<span> of a </span>chemical element<span> is a measure of the size of its atom.
</span>The atomic radius varies with increasing atomic number, but usually increases because of increasing of number of electrons.
The atomic radius decreases across the periods because an increasing number of protons, because <span>greater attraction between the protons and electrons.</span>
Answer:
Density (ρ) = 5 kilogram/cubic meter
Explanation:
Steps:
ρ =
m
V
=
10 kilogram
2 cubic meter
= 5 kilogram/cubic meter
Moseley established a more accurate periodic table by closer determination of atomic numbers. Through the results of his measurements of the wavelengths of the X-ray spectral lines of a number of elements which showed that the ordering of the elements by atomic number.