The formation of a precipitate is an indication of a chemical change.

a. True

b. False

Mole is taken in units of gram-mole. on this basis, how many atoms are there in a pound-mole of a substance?

What type of bond between water molecules pulls them into this tight ball?

What is the molar mass of fluorine, F2? 9.00 g/mol 18.00 g/mol 19.00 g/mol 38.00 g/mol

Many objects have both kinetic and potential energy. List two examples of these.

How many electrons does magnesium have in its highest energy level?

Which of the following is not true of science? 1. Science offers proof of a claim 2. Science is a way of knowing 3. Science is a process 4. Science provides support or fails to provide support to claim

What happens to the velocity of a sound wave in air if the temperature of the air increases

Determine the [oh-] concentration of a 0.741 m koh solution at 25°c.

In the lab, students decomposed a sample of calcium carbonate by heating it over a Bunsen burner and collected carbon dioxide according to the following equation: CaCO3 (s) CaO (s) CO2 (g) (a) How many mL of carbon dioxide gas were generated by the

J. J. Thomson A) Electrons are in orbital levels. John Dalton B) Atoms are the smallest unit of an element. Ernest Rutherford C) Electrons are scattered within the atom. Niels Bohr D) Protons are at the center of an atom.