science!

what is the atomic number of hydrogen?

1

what is the atomic mass of sodium?

11

atomic mass of sulfur?

16

atomic mass of helium?

2

how many valence electrons do atoms of elements 3-12 have?

3 or more

what is the name of the element that has the symbol Ca?

Calcium

what is the symbol of iron?

Fe

what is the symbol of hydrogen?

H

the number of the outermost electrons in an atom's electron cloud largely determine an atom's?

chemical properties

what are columns called on the periodic table?

groups

elements are arranged in columns on the period table based of what?

similarities in their chemical properties

within each group on the periodic table, the atoms of each element generally have

the same number of valence electrons

what are the outermost electrons in an atom's electron cloud called?

valence electrons