1.
The three basic components of an atom are:
Correct Answer
C. Protons, neutrons, electrons
Explanation
The three basic components of an atom are protons, neutrons, and electrons. Protons are positively charged particles found in the nucleus of an atom, while neutrons are neutral particles also found in the nucleus. Electrons are negatively charged particles that orbit around the nucleus in specific energy levels. These three components together determine the properties and behavior of an atom.
2.
An element is determined by its number of:
Correct Answer
B. Protons
Explanation
An element is determined by its number of protons because the number of protons in an atom defines its atomic number, which is unique to each element. The atomic number determines the element's properties and its position in the periodic table. Neutrons and electrons can vary in number within an element's atoms, resulting in different isotopes and ions, but the number of protons remains constant.
3.
The nucleus of an atom consists of:
Correct Answer
D. Protons and neutrons
Explanation
The nucleus of an atom consists of protons and neutrons. Protons have a positive charge, while neutrons have no charge. The protons and neutrons are tightly packed together in the center of the atom, forming the nucleus. The electrons, which have a negative charge, orbit around the nucleus in specific energy levels. Therefore, the correct answer is "Protons and neutrons."
4.
A protons and an electron have what charges?
Correct Answer
A. Positive and negative
Explanation
Protons have a positive charge, while electrons have a negative charge. Therefore, a proton and an electron have opposite charges, with the proton being positive and the electron being negative.
5.
Which particles have approximately the same size and mass?
Correct Answer
B. Protons and neutrons
Explanation
Protons and neutrons have approximately the same size and mass. Protons have a positive charge and are located in the nucleus of an atom, while neutrons have no charge and are also found in the nucleus. Both particles are much larger and heavier than electrons, which are negatively charged and orbit the nucleus. Therefore, the correct answer is that protons and neutrons have approximately the same size and mass.
6.
The atomic number of an atom is:
Correct Answer
A. Its 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, ensuring that the atom remains electrically neutral. Neutrons, on the other hand, are neutral particles and do not contribute to the atomic number. Ions are charged atoms that have gained or lost electrons, so they are not directly related to the atomic number.
7.
Changing the number of neutrons in an atoms nucleus changes its:
Correct Answer
D. Isotope
Explanation
Changing the number of neutrons in an atom's nucleus changes its isotope. Isotopes are atoms of the same element that have different numbers of neutrons. Since neutrons have no charge, changing their number does not affect the atom's charge. The element of an atom is determined by the number of protons in its nucleus, while an ion is an atom that has gained or lost electrons, resulting in a different charge. Therefore, the only option left is isotope, which is the correct answer.
8.
When you change the number of electrons of an element, you produce a different:
Correct Answer
C. Ion
Explanation
When you change the number of electrons of an element, you produce a different ion. An ion is an atom or molecule that has gained or lost electrons, resulting in a positive or negative charge. Changing the number of electrons alters the overall charge of the atom, creating an ion with different chemical properties than the neutral element.
9.
According to atomic theory, electrons are usually found:
Correct Answer
A. 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. The electron cloud represents the region where electrons are most likely to be found, and it extends far beyond the nucleus. This is due to the electrostatic forces of attraction between the negatively charged electrons and the positively charged protons in the nucleus. Therefore, the correct answer is that electrons are usually found outside the nucleus and often far from it.
10.
Which two sub-atomic particles are attracted to each other and why?
Correct Answer
B. Protons and Electrons, because of electrostatic attraction
Explanation
Protons and Electrons are attracted to each other because of electrostatic attraction. Protons have a positive charge, while electrons have a negative charge. Opposite charges attract each other, so the positive protons and negative electrons are attracted to each other. This electrostatic attraction is what keeps the electrons in orbit around the nucleus of an atom.