We use the following formula to calculate the number of atoms:
n (mol) = N(number of atoms) / NA
N(He) = n(mol) · NA
N(He) = 2,0 moles · 6.02·1023 = 12.04·1023 atoms
4 elements are classified in group 4 like titanium, zirconium, hafnium and ruthorfordium
P =mgh
You have mass, g =9.8 m/s2 and height calculate the potential energy P
Nobody specifically made the periodic table but it was first thought of by Dmitri Mendeleev in 1869.
Tungsten has the highest melting point (6192°F) of all metals in their pure form.