Many properties change as you move from left to right on the Periodic Table. For example: atomic number increases; electronegativity increases; atomic radii decrease etc. etc.
Increasing (valance) electrons.
The periodic table is arranged from left to right in the order of atomic numbers.
More subatomic particles, more mass
Across a period, as we move from left to right, the electronegativity increases in the periodic table.
When you move from left to right on the periodic table, the atomic number of the elements increase.
Electronegativity increases as we move from left to right on the periodic table.
The metalloids split the table these are a diagonal group of elements, B, Si, Ge, As, Sb and Te. To their right are the non metals to the left the metals. There are many more metals than any other type of element. See Wikipedia article "Periodic table (metals and non metals)"
They occupy all but the top right corner of the table.
Electronegativity increases from left to right and decreases from top to bottom on the periodic table.
Electronegativity generally increases from left to right across a period and decreases down a group in the periodic table. This trend occurs because elements on the right side of the periodic table have a greater ability to attract electrons due to increased nuclear charge and effective nuclear charge.
Periods on the periodic table are the horizontal rows that go from left to right.
As you move left to right on the periodic table, the number of valence electrons an element has increases. The number of valence electrons an element has corresponds to which group (column) an element is. (This rule does not apply to transition metals...)