Jack's teacher has a box of objects. He asks each student to pull out an object and identify whether it is a mixture or a pure substance.

What is common about these molecules? a. their atoms are held together by covalent bonds. b. they are all made up of the same two atoms. c. their atoms are held together by ionic bonds. d. they are all made up of oxygen atoms only.

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

3) in peaches, [oh]=3.16x10-11 m a) find [h+ ] b) what is the ph? c) is the solution acidic, basic, or neutral?