Chemistry Quiz 2 (Atoms)

1. The element nitrogen has a mass of 14 and 7 protons and 7 electrons. How many neutrons?

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.

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.

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2. The mass of the atom is located

In the nucleus

In the electron cloud

In the protons only

In the electrons only

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.

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.

3. An atom that is electrically stable will have the same number of protons and electrons.

True

False

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.

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.

4. The nucleus contains (check all that apply)

Protons

Neutrons

Electrons

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.

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.

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5. In order to figure out the mass, what two numbers are added?

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.

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.

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6. 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

Neutrons are the same as protons

The mass must be rounded because you can not have 0.9 of a neutron.

The mass number is the same as the number of neutrons.

Sodium is not really an element since she can't find it on the periodic table.

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.

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.

7. Which of the following is correct?

Protons are positive but have no mass.

Protons are neutral with a mass of 1.

Electrons are negative and have no mass.

Electrons are positive and have no mass.

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.

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.

8. The correct term for the protons, neutrons and electrons is

Subatomic particles

Atomic parts

Elemental particles

Charged particles

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.

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.

9. How are all elements unique?

The mass number

The atomic number

Their appearance

Their state of matter

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.

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.