Question

elements and the periodic table assessment

1. what is the center of an atom called?

a. electron cloud
b. nucleus
c. valence shell
d. energy level

1. which subatomic particle has a positive charge?

a. electron
b. neutron
c. proton
d. nucleus

1. who discovered the neutron?

a. thomson
b. dalton
c. curie
d. chadwick

1. the atomic number of an element equals the number of:

a. protons
b. neutrons
c. electrons in the outermost shell
d. protons plus neutrons

1. where are electrons found in an atom?

a. in the nucleus
b. in the energy levels surrounding the nucleus
c. in the proton
d. in the neutron

1. which model described atoms as having electrons embedded in a positive \pudding\?

a. nuclear model
b. bohr model
c. plum pudding model
d. rutherford model

1. elements in the same group of the periodic table share:

a. the same number of protons
b. the same atomic mass
c. similar chemical properties
d. the same number of neutrons

Explanation:

1. The dense central core of an atom is its nucleus.
2. Protons are positively charged subatomic particles.
3. James Chadwick is credited with discovering the neutron.
4. An element's atomic number is defined by its proton count.
5. Electrons occupy energy levels (electron cloud) around the nucleus.
6. The plum pudding model describes electrons in a positive "pudding" matrix.
7. Elements in the same periodic table group have the same valence electron configuration, leading to similar chemical properties.

Answer:

1. B. Nucleus
2. C. Proton
3. D. Chadwick
4. A. Protons
5. B. In the energy levels surrounding the nucleus
6. C. Plum pudding model
7. C. Similar chemical properties