Physical Science Chapter 4

Oxygen's atomic number is 8. This means that an oxygen atom has

• eight neutrons in its nucleus.

• a total of eight protons and neutrons.

• eight protons in its nucleus

• a total of eight neutrons and electrons

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NGSS.MS-PS1-1

According to Rutherford's model of the atom, electrons behave like

• a. planets orbiting the sun.

• b. waves on a vibrating string.

• c. light energy in a vacuum.

• d. planets rotating on their axes.

A mole is an SI base unit that describes the

• a. mass of a substance.

• b. amount of a substance.

• c. volume of a substance.

• d. electric charge of a substance.

Which statement about the atom's nucleus is correct?

• a. The nucleus is made of protons and neutrons and has a negative charge.

• b. The nucleus is made of protons and neutrons and has a positive charge.

• c. The nucleus is made of electrons and has a positive charge.

• d. The nucleus is made of electrons and has a negative charge.

Which statement about the modern model of the atom is not true?

• a. Electrons can be found between energy levels.

• b. Electrons can be found only in certain energy levels.

• c. The precise location of electrons cannot be predicted.

• d. Electrons are most likely to be found in orbitals.

If the average atomic mass of carbon is 12.01 u, 1 mole of pure carbon will have a mass of

• 12.01g

• 12 mol.

• 6g

• 6 mol.

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NGSS.HS-PS1-7

You have 6.50 mol of chromium, which has a molar mass of approximately 52 g/mol. What is the mass in grams of this amount of chromium?

• c. 338 g

• d. 3.38 kg

Which statement about an element's average atomic mass is correct?

• a. It is determined by counting the number of isotopes in a sample of the element.

• b. It is equal to one-twelfth the mass of the most common isotope.

• c. It is a weighted average, so common isotopes have a greater effect than uncommon ones.

Dalton's atomic theory stated that every element was made of atoms that could not be subdivided, atoms of the same element are alike, and

• a. atoms are made of protons, neutrons, and electrons.

• b. the nucleus is the center of the atom.

• c. atoms of different elements could form to join compounds.

• d. atoms are constantly in motion.

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NGSS.MS-PS1-5

The average atomic mass of potassium is approximately 39 u. What is the mass of 2.0 mol of potassium?

• a. 3.38 g

• b. 33.8 g

• c. 39 g

• d. 78 g

Tags

NGSS.HS-PS1-7