Question

assess it!
directions: answer each question below.

1. what is the smallest unit of an element that retains its chemical properties?

a) molecule
b) atom
c) compound
d) ion

1. which subatomic particle has a positive charge?

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

1. the atomic number of an element is determined by the number of:

a) neutrons
b) electrons
c) protons
d) nuclei

1. what do you call the vertical columns on the periodic table?

a) rows
b) periods
c) groups
d) families

1. which element is essential for life and is found in all organic compounds?

a) oxygen
b) carbon
c) hydrogen
d) nitrogen

1. what is the total number of electrons that can occupy the first energy level (the closest to the nucleus) of an atom?

a) 2
b) 4
c) 6
d) 8

1. which subatomic particle is found outside the nucleus of an atom?

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

1. the elements in the periodic table are arranged in order of increasing:

a) atomic mass
b) number of neutrons
c) number of electrons
d) atomic number

1. elements in the same group (or family) on the periodic table have:

a) the same number of neutrons
b) similar chemical properties
c) the same atomic mass
d) different atomic numbers

1. which element is a noble gas?

a) oxygen
b) nitrogen
c) neon
d) sodium

1. which of the following elements is a metal?

a) oxygen
b) chlorine
c) sodium
d) fluorine

1. which element is the most abundant in earths crust?

a) oxygen
b) silicon
c) iron
d) aluminum

Explanation:

1. An atom is the smallest unit of an element that retains its chemical properties. A molecule is made of atoms, a compound is a substance formed from two or more elements, and an ion is a charged atom or molecule.
2. Protons have a positive charge. Neutrons are neutral, electrons are negative, and the nucleus is not a subatomic particle (it contains protons and neutrons).
3. The atomic number is determined by the number of protons. Electrons can be lost or gained (in ions), neutrons vary in isotopes, and nuclei is not a count.
4. Vertical columns on the periodic table are called groups (or families). Rows are periods.
5. Carbon is essential for life and found in all organic compounds.
6. The first energy level can hold 2 electrons.
7. Electrons are found outside the nucleus. Protons and neutrons are in the nucleus, and the nucleus is not a subatomic particle.
8. Elements in the periodic table are arranged in order of increasing atomic number.
9. Elements in the same group have similar chemical properties. They can have different neutrons (isotopes), different atomic masses (due to isotopes), but same atomic number range (for the group).
10. Neon is a noble gas. Oxygen and nitrogen are non - metals (not noble gases), sodium is a metal.
11. Sodium is a metal. Oxygen, chlorine, and fluorine are non - metals.
12. Oxygen is the most abundant element in Earth's crust.

Answer:

1. b) Atom
2. a) Proton
3. c) Protons
4. c) Groups
5. b) Carbon
6. a) 2
7. b) Electron
8. d) Atomic number
9. b) Similar chemical properties
10. c) Neon
11. c) Sodium
12. a) Oxygen