Which of the following consists of positive and negative ions bound together and held in place in a crystalline solid? a. covalent bonds b. ionic compounds c. molecular compounds d. molecules

air quality

poor drinking water

and heavy polution

can lead to poor health

periodic trends is an atom that gets larger as the number of electronic shells increase, the radius of atoms increases as you go down a certain group in the periodic table of elements. in general, the size of an atom will decrease as you move from left to right of a certain period.