Atoms, which are always neutral in electric charge, contain electrons as well as protons and neutrons. An electron has an electrical charge of - 1. If an atom has three electrons, infer how many protons it has.

What does it means when people says that energy is as old as time itself

An element has atomic number 10 and an atomic mass of 20. How many neutrons are in the atom of this element? A. 10 B. 20 C. 30 D. 0 E. 200

How many moles of water 9.31 x 10^22

What is the pH of a buffer solution when the concentrations of both buffer components (the weak acid and its conjugate base) are equal? What happens to the pH when the buffer contains more of the weak acid than the conjugate base?

Lt takes 4 hr 39 min for a 2.00-mg sample of radium-230 to decay to 0.25 mg. what is the half-life of radium-230?

What is the number of moles of 27.6g of lithium?

Air is transferred from a 75 L tank where the pressure is 125 psi and the temperture is 288 k to a tire with a volume of 6.1 L and a pressure of 25 psi. What is the new temperture.

Which of the following is a measure of randomness in a system? A) entropy. B) kinetic energy. C) potential energy. D) chemical energy.

What substance can be broken down by chemical means? A) ammonia B) aluminum C) antimony D) argon (Castle learning question)

How the law of conservation of mass could be useful for investigating chemical changes