12. Which of the following is true about the Earth's crust? 1) It floats above a layer of flowing hot magma.

2) It is the thickest layer of the Earth.

3) It is the hottest layer of the Earth.

4) It mostly consists of iron.

What substance has a mass of 9.5g and volume of 2.1cm^3

What energy is it when you flip on a switch on a lamp

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.