They have microscopes to see small objects such as atoms and molecules
In atomic models balls represent an atom
Now if an atom like carbon has four holes it means it can bond with four atoms. It has valency = 4.
The atomic number of carbon is 6
the configuration is 1s2 2s2 2p2
So due to four valence electrons it can bind with four other atoms and thus we have four holes in carbon ball
The hydrogen show a valency of one
the atomic number of hydrogen = 1
its configuration is 1s1
So it can bind with one atom (max) thus we have one hole in hydrogen ball
Metals are located on the left of the periodic table, and nonmetals are located on the upper right.
Explanation: Metals: Lustrous (shiny)
Good conductors of heat and electricity.
High melting point.
High density (heavy for their size)
Malleable (can be hammered)
Ductile (can be drawn into wires)
Usually solid at room temperature (an exception is mercury)
Opaque as a thin sheet (can't see through metals)
Nonmetals: High ionization energies.
High electronegativities.
Poor thermal conductors.
Poor electrical conductors.
Brittle solids—not malleable or ductile.
Little or no metallic luster.
Gain electrons easily.
Dull, not metallic-shiny, although they may be colorful
If by classical you mean formula name it is CrPO4<span>.</span>