this one

Question 1

periodic

Answer 1

describes something that occurs or repeats

Question 2

periodic law

Answer 2

repeating chemicals and physical properties of elements change

Question 3

period

Answer 3

in chemistry a horizontal row of elements in the periodic table

Question 4

group

Answer 4

a vertical column of elements in the periodic table

Question 5

alkali metal

Answer 5

one of the elements of group 1

Question 6

alkaline earth metal

Answer 6

one of the elements of group 2

Question 7

halogen

Answer 7

one of the elements of group 17

Question 8

noble gas

Answer 8

one of the elements of group 18