alkali metal
potassium
Calcium. The first two are beryllium and magnesium.
Potassium
Li Lithium
Sodium (Na)
vagina
The first element in a period is an alkali metal.
Sodium is a metal in Group 1 and Period 3 of the Periodic table. It is an alkali-metal.
Rubidium is an alkali metal (group 1, period 5)
Sodium (Na) is Group 1, Period 3
The alkali metals are more reactive.
potassium
alkali metal
alkali metal
Calcium. The first two are beryllium and magnesium.
Potassium