Is a compound considered a pure substance?

It depends on which compound you use carbon dioxide can be while helium will not but if you where to sum it up it would be use because simply most compounds are considered pure substance.

Explanation:

The second rover has a greater mass.

Explanation:

Given data,

The weight of the space rover on earth, W = 100 N

                                       W = mg

                                        m = W /g

                                            = 100 / 9.8

                                            = 10.2 kg

Hence, the mass of the space rover on earth is, m = 10.2 kg

The weight of the different space rover on moon W' = 100 N

                                        W' = mg'

                                         m = W'/g'

                                             = 100 / 1.6   (acceleration due to gravity on moon g' = 1.6 ,m/s²)

                                          m = 62.5 kg

Hence, the second rover has a greater mass.