Electrons and Energy Levels-8th

The model represents an atom. What does the number in the outside circle represent?

• the number of protons in the atom

• the number of neutrons in the atom

• the number of electrons in the atom

• the number of nuclei in the atom

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The model represents an atom. Reference the periodic table. An atom of which element does this model represent?

• nickel

• silicon

• palladium

• barium

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The model represents an atom. How many valence electrons is an atom of this element likely to have?

• 0

• 1

• 2

• It will vary.

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Which of the following statements about electrons is NOT true?

• Electrons closest to the nucleus have the most energy.

• The space electrons in an atom occupy is much larger than the nucleus.

• Electrons are shared between atoms in a chemical bond.

• Valence electrons are the outermost electrons in an atom.

Most atoms form chemical bonds with other atoms. Why is this true?

• to gain more energy

• to become more stable

• to share valence electrons

• to gain more electrons

Which of the following is a chemical compound?

• neon

• gold

• water

• oxygen

Aluminum oxide is a chemical compound with two aluminum atoms and three oxygen atoms. Which is the correct chemical formula for aluminum oxide?

• Al3O2

• 2AlO3

• 2Al3O

• Al2O3

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What are stable elements called that are found on the last row of the periodic table?

• metals

• nonmetals

• noble gases

• halogens

The image above shows an electron dot diagram for silicon. How many total bonds can one atom of this metalloid make with other atoms?

• 4

• 3

• 1

• 10

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Why are noble gases not often found as parts of compounds in nature?

• Their valence electrons are absent.

• Their valence electrons are moving.

• Their valence electrons are neutral.

• Their valence electrons are stable.

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