1.
The mass of the atom is located
Correct Answer
A. In the nucleus
Explanation
The mass of an atom is located in the nucleus. The nucleus is the central part of an atom that contains protons and neutrons, which have mass. Electrons, on the other hand, are much lighter and are located in the electron cloud surrounding the nucleus. Therefore, the majority of the mass of an atom is concentrated in the nucleus.
2.
The nucleus contains (check all that apply)
Correct Answer(s)
A. Protons
B. Neutrons
Explanation
The nucleus is the central part of an atom, and it contains protons and neutrons. Protons have a positive charge, while neutrons have no charge. Electrons, on the other hand, are found outside the nucleus in the electron cloud and have a negative charge. Therefore, the correct answer is protons and neutrons because electrons are not found in the nucleus.
3.
How are all elements unique?
Correct Answer
B. The atomic number
Explanation
The atomic number of an element refers to the number of protons in the nucleus of an atom. Each element has a unique atomic number, which means that no two elements have the same number of protons. This is why all elements are unique. The mass number, appearance, and state of matter are not factors that determine the uniqueness of an element.
4.
An atom that is electrically stable will have the same number of protons and electrons.
Correct Answer
A. True
Explanation
An atom that is electrically stable will have the same number of protons and electrons because protons have a positive charge and electrons have a negative charge. In order for an atom to be electrically stable, the positive and negative charges must balance each other out. If an atom has more protons than electrons, it will have a positive charge and if it has more electrons than protons, it will have a negative charge. Therefore, for an atom to be electrically stable, it must have an equal number of protons and electrons.
5.
Which of the following is correct?
Correct Answer
C. Electrons are negative and have no mass.
Explanation
The answer is "Electrons are negative and have no mass." This is because electrons are negatively charged particles found in atoms and they have a very small mass compared to protons and neutrons. Protons, on the other hand, are positively charged particles with a mass of 1. So, the statement that electrons are negative and have no mass is correct.
6.
The element nitrogen has a mass of 14 and 7 protons and 7 electrons. How many neutrons?
Correct Answer
7
seven
Explanation
Nitrogen has a mass number of 14, which is the sum of its protons and neutrons. Since it has 7 protons, the number of neutrons can be calculated by subtracting the number of protons from the mass number. Therefore, nitrogen has 7 neutrons. The word "seven" is just another way of expressing the numerical value of 7.
7.
In order to figure out the mass, what two numbers are added?
Correct Answer
protons and neutrons
neutrons and protons
Explanation
The correct answer is "protons and neutrons". When determining the mass of an atom, we need to consider the combined mass of the protons and neutrons present in the nucleus. These subatomic particles contribute to the overall mass of the atom. Therefore, adding the numbers of protons and neutrons will give us the total mass of the atom.
8.
Jamie and Sally are working on their homework together. Jamie said that sodium must have 11.9 neutrons because the mass is 22.9 and the atomic number is 11. Sally explained that this is incorrect because
Correct Answer
B. The mass must be rounded because you can not have 0.9 of a neutron.
Explanation
The explanation provided states that the mass must be rounded because it is not possible to have a fraction of a neutron. Neutrons are subatomic particles with a mass of approximately 1 atomic mass unit, and they cannot exist in fractional amounts. Therefore, the mass of an element should always be a whole number, and any decimal value should be rounded to the nearest whole number.
9.
The correct term for the protons, neutrons and electrons is
Correct Answer
A. Subatomic particles
Explanation
The term "subatomic particles" refers to the protons, neutrons, and electrons that make up an atom. These particles are smaller than an atom and are the fundamental building blocks of matter. The term "atomic parts" is too generic and does not specifically refer to these particles. "Elemental particles" is not a commonly used term and may cause confusion. "Charged particles" is not accurate as neutrons are not charged. Therefore, "subatomic particles" is the correct term to describe protons, neutrons, and electrons.
10.
What is the difference between the mass number and the atomic number of an atom?