If element X has 31 protons, how many electrons does it have?

4. How does density affect refraction of a lightwave?

A boy pulls a sled 46 m across a flat field with a force of 120 N. The force acts on the sled through a rope at a 23° angle with the horizontal. What is the work the boy does on the sled? (Round your answer to two significant figures.)

What is one important characteristic that all Protists share that makes them different from bacteria?

We can use the Doppler Effect to study the movements of far away stars and galaxies. True False

Uranus is a pale green planet, with 27 satellites and several rings. True or False P. S what subject would this be

Three liquids are at temperatures of 5 ◦C, 25◦C, and 34◦C, respectively. Equal masses of the first two liquids are mixed, and the equilibrium temperature is 17◦C.

The air you breathe is an example of a (n) ?

How do fluids move? Explain.

How does the interior of the earth relate to what occurs on the surface?

If a atom loses a neutron what happens