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The volumes of four samples of gaseous compounds at 298 K and 101.3 kPa are shown in the table above.

Which two samples contain the same number of molecules?

• 1 and 2

• 1 and 3

• 2 and 3

• 2 and 4

Which particle diagram represents a sample of oxygen gas at STP?

• 1

• 2

• 3

• 4

Which electron configuration represents the electrons in an atom of sulfur in an excited state?

• 2-8-6

• 2-7-7

• 2-8-7

• 2-7-8

According to the kinetic molecular theory, which statement describes the particles in a sample of an ideal gas?

• The particles are constantly moving in circular paths.

• The particles collide, decreasing the total energy of the system.

• The particles have attractive forces between them.

• The particles are considered to have negligible volume.

Which electron shell in an atom of calcium in the ground state has an electron with the greatest amount of energy?

• 1

• 2

• 3

• 4

In all atoms of bismuth, the number of electrons must equal the

• number of protons

• number of neutrons

• sum of the number of neutrons and protons

• difference between the number of neutrons and protons

Which particle model diagram represents xenon at STP?

• 1

• 2

• 3

• 4

During all chemical reactions, charge, mass and energy are

• condensed

• conserved

• decayed

• decomposed

Compared to the energy of an electron in the second shell of an atom of sulfur, the energy of an electron in the

• first shell is lower.

• first shell is the same.

• third shell is lower.

• third shell is the same.

The average kinetic energy of the particles in a sample of matter is expressed as

• density

• volume

• pressure

• temperature