What is a tough, rigid, outer covering that protects some cells and gives them shape?

One way a machine can make work easier is by?

Which properties are most useful for identifying minerals? Why?

Which process releases heat? A. Grilling vegetables B. Frying an egg C. Boiling water D. Setting off a firecracker

How many atoms of hydrogen (h) are present in 200 molecules of ammonia (nh3) ? express your answer numerically?

If a molecule is taking up more space is it gaining or losing energy explained

A chemical engineer is developing a process for producing a new chemical. One step in the process involves allowing a solution of potassium hydroxide to react with a solid. Which action would most likely increase the reaction rate for this step?

Determine which elements are balanced and unbalanced for each chemical equation below when every compound is given a coefficient of one.

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is salt and Solution B is salt. She wants to obtain ounces of a mixture that is salt.

Reactions that affect the nucleus of an atom are called? A. Fusions B. Radioactive decays C. Nuclear reactions D. Fissions

The amplitude of a wave is most directly related to what wave characteristic? Crest length Frequency Wavelength Wave height