Mass does not change during a chemical change. is the same true for physical change?

A molecule of chlorine has atoms of the same element, and a molecule of carbon dioxide has different kinds of atoms. based on this information, chlorine is and carbon dioxide is.

An atom is electrically neutral when it has no extra electrons in its valence shell. the number of electrons equals the number of neutrons. the number of electrons equals the number of protons.

5. Express the composition of each atom in shorthand form. a. zinc-64 b. chlorine-37 c. hydrogen-3 d. calcium-40

About oxidation and reduction, write a definition of each in your own words

What is the molar mass of (NH4) 2O? Explain how you calculated this value.

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?