What are the vertical linings of the elements called?
Groups
What are the horizontal linings of the elements called?
Periods
What does the atomic number of an element determine?
It’s position in the periodic table
What does the number of electrons in an elements highest energy level determine?
It’s chemical properties
What does the group number equal?
The number of electrons in the outermost shell
Why do thyroid of elements have the same chemical properties?
They have the same number of electrons in their outermost shell
Why do the atoms get larger going down a group in the periodic table?
They have more energy levels so the atoms are larger
What happens between the electrons and the nucleus of an atom as the atoms get larger?
The electrons in the highest occupied energy level are less strongly attracted so they are more reactive
What happens to the reactivity in metals as you go down the group?
It increases
Why does the reactivity of metals increase going down the group?
Because they lose electrons so they lose an energy level so the atom is smaller and the attraction between the nucleus and the electrons grows
Why does the reactivity in non metals decrease as you go down the group?
Because they gain electrons so they gain an energy level so the atom is bigger and the attraction between the nucleus and the electrons weakens
When did scientists find out about protons and electrons?
At the start of the 1900’s
