Which of the following is a pure substance?

brass

sodium

rocks

steel

What happens to the gas particles in an inflated ball when it gets a hole? why?

Which of the following statements about subatomic particles best characterizes protons? positive charge, heavy, found in the nucleus of an atom no charge, heavy, found in the nucleus of an atom negative charge, light, circling the nucleus of an atom

Which region contains elements with two valence electrons?

A bird sitting on a tree flies away as you walk by. Which of the characteristics explains the bird's behavior?

How do you convert 3270 mg to kg?

What does it mean when there are 2.3 x 10-4 moles?

Electric force is an A. attraction and repulsion between protons and electrons . B. attraction and repulsion between protons and neutrons. C. attraction and repulsion between neutrons and electrons.

A salt crystal has a mass of 0.18 mg. how many nacl formula units does it contain?

Which of the following is easist to accelerate? A. bowling ball B. tennis ball C. golf ball D. ping pong ball

Fish need at least 4 ppm dissolved o2 for survival. part a what is this concentration in mol/l?