Which of the following is a pure substance? choose all that apply.

a. fruit cake
b. nickel
c. saltwater
d. rust

100mg magnesium reacts with 20ml of 1.0m hcl

1) a light bulb takes in 30 of energy per second. it transfers 3j as use energy. calculate the efficiency. second. it transfers 3j as useful light energy and 27j as heat energy. calculate the efficiency

Which statement describes the arrhenius interpretation of acids and bases?