Max wants to find out what variables affect the rate at which sugar dissolves in water. He records different information about four containers of water and sugar, as shown in the table below. Which two containers should Max choose to investigate the effects that different temperatures have on the rate at which sugar dissolves?

1 and 2

1 and 3

2 and 3

2 and 4

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

answer; 4 electrons;