How many protons are in an element with an atomic number of 8 and a mass number of 18?

18

10

8

3

The pressure of a gas contained in a cylinder with a movable piston is 300 Pa. The area of the piston is 0.5 m². Calculate the force that is exerted on the piston.

What is required for the offspring to have a dominant trait

Which statement about satellite motion is true? A. A satellite uses rocket fuel to steer itself around Earth. B. A satellite in orbit continuously falls toward Earth. C. Gravity does not act on a satellite once it is in orbit. D.

Our sun is in which stage of its life cycle? A. red giant B. main sequence C. white dwarf D. protostar

Were you able to move the refrigerator? if not, what would you have to change? describe what you did

What conclusion can be drawn from the statement that an element has high electron affinity, high electronegativity, and a high ionization energy? A) The element is most likely from Group 1A or 2A and in period 1 or 2.

When a cyclist rides past you on the street, this is an example of

Why are galaxies visible

I hockey puck slides across an ice rink more easily than it does across a rough concrete surface why is this

Sodium-22 Sodium-25 # of protons # of neutrons # of electrons