Unit 1: The Atom

Elements within the same group in the periodic table have similar properties because they have the same number of

• Protons

• Neutrons

• Ions

• Valence electrons

The order of elements in the periodic table is based on

• the number of protons in the nucleus

• the electric charge of the nucleus

• the number of neutrons in the nucleus

• atomic mass

Which of the following elements is an alkali metal?

• Calcium

• Magnesium

• Chlorine

• Sodium

Nonmetals are found in which area of the periodic table?

• on the left-most side <-

• on the right side ->

• in the middle column of the periodic table

• in the bottom rows

Elements that share properties of both metals and nonmetal are called

• ions

• periods

• metalloids

• halogens

Which statement about noble gases is correct?

• They form compounds with very bright compounds

• They are not reactive with other elements

• They are highly reactive with both metals and nonmetals

• They have 7 valence electrons

Which element is a metalloid?

• Aluminum

• Gallium

• Arsenic

• Selenium

Different isotopes of the same element have different

• atomic numbers

• number of neutrons

• numbers of protons

• numbers of electrons

Which statement correctly describes protons and neutrons?

• They have the same mass and the same electrical charge

• They have the same mass but different electrical charges

• They have different masses but the same electrical charge

• They have different masses and different electrical charges

Which element does the shell model represent?

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