Help please! What is the outcome of all chemical changes when two substances are combined?

A- A new substance forms with identical properties

B- The two substances release an odor

C- The two substances change color

D- A new substance forms with different properties

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers