1.
The three basic
components of an atom are:
Correct Answer
B. Protons, neutrons, and electrons
Explanation
An atom consists of protons, neutrons, and electrons. Protons have a positive charge, neutrons have no charge, and electrons have a negative charge. Protons and neutrons are located in the nucleus of the atom, while electrons orbit around the nucleus in energy levels. These three components are essential for the structure and stability of an atom. Ions are charged particles that can be formed when an atom gains or loses electrons, so they are not considered as basic components of an atom.
2.
An element is
determined by the number of:
Correct Answer
D. Protons
Explanation
The number of protons in an element determines its identity. Protons are positively charged particles found in the nucleus of an atom. Each element has a unique number of protons, known as its atomic number. This number determines the element's place in the periodic table and its chemical properties. Therefore, the correct answer is protons.
3.
The nucleus of an atom
consists of:
Correct Answer
C. Protons and neutrons
Explanation
The nucleus of an atom consists of protons and neutrons. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, orbit around the nucleus in electron shells. Therefore, the correct answer is protons and neutrons.
4.
A single proton has
what electrical charge?
Correct Answer
B. Positive charge
Explanation
A single proton has a positive charge because it contains one unit of positive electrical charge. Protons are one of the fundamental particles that make up an atom, along with neutrons and electrons. While electrons have a negative charge and neutrons have no charge, protons have a positive charge. This charge is essential for the stability and interactions of atoms, as protons attract electrons and form the nucleus of an atom.
5.
Which particles have
approximately the same size and mass as each other?
Correct Answer
C. Protons and neutrons
Explanation
Protons and neutrons have approximately the same size and mass as each other. Protons have a positive charge and are located in the nucleus of an atom, while neutrons have no charge and are also located in the nucleus. Both protons and neutrons are much larger and heavier than electrons, which are negatively charged and orbit the nucleus. Therefore, the correct answer is protons and neutrons.
6.
Which two particles
would be attracted to each other?
Correct Answer
B. Electrons and protons
Explanation
Electrons and protons would be attracted to each other because electrons carry a negative charge and protons carry a positive charge. Opposite charges attract each other according to the laws of electrostatics. Neutrons, on the other hand, carry no charge, so they would not be attracted to any charged particle. Therefore, the correct answer is electrons and protons.
7.
The atomic number of an
atom is:
Correct Answer
C. The number of protons
Explanation
The atomic number of an atom refers to the number of protons in its nucleus. Protons are positively charged particles and are responsible for determining the element's identity. The number of electrons in an atom is equal to the number of protons in a neutral atom, but the atomic number specifically refers to the number of protons. Neutrons, on the other hand, do not affect the atomic number and can vary within the same element, resulting in different isotopes.
8.
Changing the number of
neutrons of an atom changes its:
Correct Answer
A. Isotope
Explanation
Changing the number of neutrons of an atom changes its isotope. Isotopes are variants of an element that have the same number of protons but different numbers of neutrons. By altering the number of neutrons, the atomic mass of the atom changes, resulting in a different isotope of the same element. This does not affect the element itself or its charge as the number of protons, which determines the element and its charge, remains unchanged.
9.
When you change the number of electrons on an atom, you produce a different:
Correct Answer
B. Ion
Explanation
When you change the number of electrons on an atom, you produce a different ion. An ion is formed when an atom gains or loses electrons, resulting in a different number of protons and electrons. This change in the number of electrons creates an ion with a positive or negative charge. Isotopes refer to atoms of the same element with different numbers of neutrons, while elements refer to different types of atoms with a unique number of protons. Atomic mass refers to the combined mass of protons, neutrons, and electrons in an atom.
10.
According to atomic
theory, electrons are usually found:
Correct Answer
C. Outside the nucleus and often far from it - most of an atom's volume is its electron cloud
Explanation
According to atomic theory, electrons are usually found outside the nucleus and often far from it because most of an atom's volume is its electron cloud. This means that the majority of the space within an atom is occupied by the electrons, rather than the nucleus. Electrons are negatively charged particles and are attracted to the positively charged protons in the nucleus, but they are not confined to the nucleus itself. Instead, they exist in regions of space surrounding the nucleus, forming an electron cloud.