s3 atomic structure

Which of the following elements is a semi-metal?

        A.    Beryllium

        B.    Silicon

        C.    Phosphorus

        D.    Chlorine

• A.    Beryllium

•         B.    Silicon

• C.    Phosphorus

• D.    Chlorine

Which of the following groups of elements are all non-metals?

• A. B, Si, Ne, Ar

• B. Be, Mg, Al, Li

• C. C, N, P, S

• D. O, F, Cl, Be

Which of the following statements about subatomic particles is INCORRECT?

• A.    Neutrons are electrically neutral.

• B.    A proton and a neutron have about the same mass.

• C.    All atoms contain protons, neutrons and electrons.

• D.    The mass of an atom is concentrated at the nucleus.

The atomic number and mass number of an element L are 15 and 31 respectively. The atom has

• A.    16 electrons, 16 protons and 15 neutrons.

• B.    15 electrons, 16 protons and 15 neutrons.

• C.    16 electrons, 15 protons and 16 neutrons.

• D.    15 electrons, 15 protons and 16 neutrons.

• A

• B

• C

• D

• A.    (1) and (2) only

• B.    (1) and (3) only

• C.    (2) and (3) only

• D.    (1), (2) and (3)

• A

• B

• C

• D

• A

• B

• C

• D

• A

• B

• C

• D

Which of the following statements about the structure of an atom is INCORRECT?

• A.    The nucleus is composed of electrons and neutrons.

• B.    Most of the space in an atom is empty.

• C.    Electrons move around the nucleus at a high speed.

• D.    Neutrons and protons are much heavier than electrons.