List the two main kinds of changes that you can observe when chemical reactions occur.

A sample of soil from a newly discovered cave is analyzed by a team of explorers. They find an element that is a good conductor of electricity. It also forms a chloride in the form XCl2 and an oxide in the form XO.

What's the specific heat of paraffin wax

Consider the balanced equation below. 4NH3 + 3O2 - > 2N2 + 6H2O What is the mole ratio of NH3 to N2? 2:4 4:2 4:4 7:2

Which of the following apply to carbon? Select all that apply. Carbon chains can form branches and cross-links. Carbon compounds can be rings. Carbon monoxide is an organic compound.

Which of the following would be a testable hypothesis for an experiment that compares the health of salmon raised in fish farms to salmon caught in the wild?

The following mechanism has been proposed for the gas-phase reaction of chloroform (CHCl3) and chlorine.

Catherine has some seawater. She wants to separate pure water from the seawater. She sets up the apparatus shown in the diagram below. Name the change of state that occurs at the surface of the seawater. It is a distillation diagram

Elements in the noble gas family are considered stable because

A house cat with a mass of 3.0 kg runs at a constant rate of 4.0 m/s in a straight line. What is the momentum of the cat?

Planet z-34 has a mass equal to 1/3 that of earth, a radius equal to 1/3 that of earth, and an axial spin rate 1/2 that of earth.