what is known as electronegativity and mention how the electro negativity vary long the periods and down the groups..please i need answers quickly!​

Electronegativity is a measure of an atom's ability to attract shared electrons to itself. On the periodic table, electronegativity generally increases as you move from left to right across a period and decreases as you move down a group.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)