Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number of Question 19 options: A) neutrons in its nucleus. B) protons in its nucleus. C) protons plus neutrons in its nucleus. D) electrons in the element.

How does the value of the equilibrium constant show that a reaction reaches equilibrium very quickly? (a) the equilibrium constant is large. (b) the equilibrium constant is small. (c) the equilibrium constant is zero. (d) the value of the equilibrium constant does not show how quickly a reaction comes to equilibrium.

A250 g sample of water with an initial temperatureof 98.8 closes 6500 joules of heat. what is the finaltemperature of the water?

1) a light bulb takes in 30 of energy per second. it transfers 3j as use energy. calculate the efficiency. second. it transfers 3j as useful light energy and 27j as heat energy. calculate the efficiency