Lithium and potassium have similar chemical properties because the atoms of both elements have the same
(1) mass number
(2) atomic number
(3) number of electron shells
(4) number of valence electrons

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

If blood contains 150g of hemoglobin per liter of blood, how much hemoglobin would be contained in 10 ml of blood

Chemistry worksheet - i am not sure what they are asking for exactly?