How did oxygen (O2) get into Earth's atmosphere?

What are the conditions to increase the stability of a body?

How many protons, neutrons, and electrons are in a neutral atom with the symbol 41Ca A) 20 protons, 21 neutrons, 21 electrons B) 20 protons, 21 neutrons, 20 electrons Eliminate C) 21 protons, 21 neutrons, 20 electrons D) 41 protons, 0 neutrons, 41

A generation is about one-third of a lifetime. Approximately how many generations have passed during the last 2,000 years?

Which of the following are steps of the inquiry process?

A child pulls a balloon for 12 m with a force of 1.0 n at an angle of 60 below horizontal. how much work does the child do on the balloon?

According to Newton's second law of motion acceleration or an object depends upon the ___ of the object and the ___ Acting on it. I'm confused on what the blanks are. I can't find them.

What is the concentration of H + ions at a pH = 7?

Suppose that Paul D. Trigger fires a bullet from a gun. Will the speed of the bullet leaving the muzzle will be the same as the speed of the recoiling gun? Explain.

A certain rock contains large jagged pieces of other rocks cemented by fine particles what type of rock is this explain

Could a nucleus that has one proton but no neutrons exist?