Basic Atomic Structure

Question 1

Which of the following statements is true about covalent bonds?

Covalent bonds form from the sharing of electrons between atoms
Sigma bonds are the weakest covalent bonds
The covalent bond between H-Cl is nonpolar
Covalent bonds aren’t affected by the electronegativity of the atoms

Answer 1

Covalent bonds form from the sharing of electrons between atoms

Question 2

Isotopes are __________.

types of valence shells
versions of one element with a different number of neutrons
special orbitals in metal elements
versions of one element with a different number of protons

Answer 2

versions of one element with a different number of neutrons

Question 3

Which of the following statements is true?

An orbital is a space around the nucleus of an atom where a proton is likely to be found.
An orbital is a space around the nucleus of an atom where an electron is likely to be found.
The number of orbitals that an atom has is the same for all elements.
Valence electrons reside in the innermost shell of an atom.

Answer 3

An orbital is a space around the nucleus of an atom where an electron is likely to be found.

Question 4

Atomic mass does not include ________ in its calculation. The atomic number of an element is the number of ___________.

protons; neutrons
electrons; protons
neutrons; protons
electrons; neutrons

Answer 4

electrons; protons

Question 5

An atom has 5 protons, 2 neutrons, and 5 electrons. Which of the following is the atom’s mass number?

5
7
10
12

Answer 5

7

Extra:
To calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons. In this case, you should add 5 and 2, which equals to 7. Electrons are so small, they are not factored into the atomic mass.

Question 6

The number of ________ is the same across a period but increases when moving down a group?

isotopes
electron shells
cations
anions

Answer 6

Electron shells

Extra:
you move from left to right across the periodic table (period), the atomic number increases. As you move from top to bottom (group), the number of filled electron shells increases.

Question 7

Which of the following statements is true about protons?

They have more mass than a neutron.
The number of protons in the nucleus is the defining property of an element.
Some atoms have no protons.
They have a negative charge.

Answer 7

The number of protons in the nucleus is the defining property of an element.

Question 8

Which of the following statements about ionic bonding is true?

Ions are atoms that have gained one or more protons.
Ionic bonds usually form in endothermic reactions.
It involves the electrostatic attraction between oppositely charged ions.
It involves the electrostatic attraction between similarly charged ions.

Answer 8

It involves the electrostatic attraction between oppositely charged ions.

Question 9

Which of the following statements about protons is true?

The number of protons is known as the “ionic number”
The chemical properties of atoms are defined only by protons
In chemistry, the term proton refers to the hydrogen ion, H+
They can travel around the nucleus of an atom

Answer 9

In chemistry, the term proton refers to the hydrogen ion, H+

Question 10

Which of the following statements is true about electrons?

They have more mass than a proton
They have a negative charge
They don’t participate in electromagnetic interactions
They can’t radiate or absorb energy

Answer 10

They have a negative charge

Question 11

Which of the following statements is true about the periodic table?

Periods are the vertical rows in the periodic tables
All elements in a period have the same number of electron shells
Period 2 elements involve the 5s and 5p orbitals
Group columns in the periodic table are based on neutron configurations

Answer 11

All elements in a period have the same number of electron shells

Question 12

Which of the following statements is true?

All valence shells can hold up to three electrons
Shells can contain different electron numbers based on the element
The electron shells are labeled: A, B, C, D, E, F
The valence shell is the outermost occupied electron shell

Answer 12

The valence shell is the outermost occupied electron shell

Question 13

The molecular formula for baking soda is NaHCO3 This molecule is made up of 6 ____ and 4 __________?

atoms; electrons
electrons; atoms
elements; atoms
atoms; elements

Answer 13

atoms; elements

Extra:
The formula consists of one sodium (Na) atom, one hydrogen (H) atom, one carbon (C) atom and three oxygen (O) atoms – in total 6 atoms. It contains 4 different elements – sodium, hydrogen, carbon and oxygen.

Question 14

The number of protons is the same as?

The angular momentum
Number of isotopes for the element
The atomic number
The nuclear force

Answer 14

The atomic number

Question 15

Cations can be defined as:

Positively charged ions
Negatively charged ions
Type of orbitals
Types of isotopes

Answer 15

Positively charged ions

Extra:
An ion is any atom that bears one or more positive or negative electrical charges. When an atom loses an electron, it becomes positively charged.

Positively charged ions are called cations. When an atom gains an electron, it becomes negatively charged.

Negatively charged ions are called anions.

Question 16

When an atom gains an electron it ___________.

becomes positive
becomes neutral
loses its ability to ever have a charge
becomes negative

Answer 16

becomes negative

Extra:

An ion is any atom that bears one or more positive or negative electrical charges. When an atom loses an electron, it becomes positively charged. Positively charged ions are called cations. When and atom gains an electron, it becomes negatively charged. Negatively charged ions are called anions.