How do the atomic mass and atomic number compare for helium?

a) The atomic mass is greater.

b) The atomic number is greater.

c) The atomic mass and atomic number are equal.

d) Helium does not have an atomic number.

What did Darwin observe about finches in the Galápagos Islands? a. Their feathers were adapted to match their environment. b. Their beaks were adaptations related to the foods the finches ate. c. They had identical phenotypes in all locations. d.

Compounds that are formed when two or more atoms combine to form molecules are called?

What happens to atoms after a chemical change?

Roberto throws a tennis ball to a friend. He then throws a baseball with the same amount of force. Which ball is accelerated more? Why?

What elements contain the same number of atom shells as sodium?

A common stain remover is sold in concentrated form as 3M sodium hypochlorite (NaOCl). You need to create 400 milliliters of a 0.5M solution of sodium hypochlorite to fill a spray bottle. What volume of 3M sodium hypochlorite is needed? 15.0 mL 66.

A chemical reaction that takes in heat is called: exothermic endothermic a phase change

Which of the following lines (of latitude or longitude) would represent by 180 longitude? South Pole Equator Prime meridian North Pole International date line

63Ni decays by a first-order process via the emission of a beta particle. The 63Ni isotope has a half-life of 100. years. How long will it take for 65% of the nickel to undergo decay?

Based on the standard free energies of formation, which of the following reactions represent a feasible way to synthesize the product? A. 2C (s) + H2 (g) →C2H2 (g); ΔG∘f=209.2 kJ/molB. N2 (g) + 3H2 (g) →2NH3 (g); ΔG∘f=-33.30 kJ/molC.