An atom is:

• a large molecule

• a small particle that makes up matter

• a type of chemical reaction

• a form of energy

Answer explanation

An atom is the basic unit of matter, consisting of protons, neutrons, and electrons. It is not a large molecule, a type of chemical reaction, or a form of energy, making 'a small particle that makes up matter' the correct choice.

Tags

NGSS.MS-PS1-1

An element is a substance that consists of how many types of atoms?

• One type of atom

• Two types of atoms

• Three types of atoms

• Four types of atoms

Answer explanation

An element is defined as a pure substance made up of only one type of atom. This distinguishes it from compounds, which consist of two or more types of atoms. Therefore, the correct answer is 'One type of atom'.

Tags

NGSS.MS-PS1-1

A nucleus is:

• the central part of an atom containing protons and neutrons

• a type of cell in the human body

• a type of chemical reaction

• a form of energy

Answer explanation

The nucleus is the central part of an atom, containing protons and neutrons, which are essential for defining the atom's identity and mass. The other options do not accurately describe a nucleus.

Tags

NGSS.MS-PS1-1

A proton is:

• a negatively charged particle

• a positively charged particle

• a neutral particle

• an antiparticle

Answer explanation

A proton is a subatomic particle with a positive charge, making it essential in forming atomic nuclei. Therefore, the correct answer is 'a positively charged particle'.

Tags

NGSS.MS-PS1-1

What is a neutron?

• A) A positively charged subatomic particle

• B) A negatively charged subatomic particle

• C) A neutrally charged subatomic particle

• D) A particle with no mass

Answer explanation

A neutron is a subatomic particle that carries no electric charge, making it a neutrally charged particle. This distinguishes it from protons, which are positively charged, and electrons, which are negatively charged.

Tags

NGSS.MS-PS1-1

What is an electron?

• A) A positively charged subatomic particle

• B) A negatively charged subatomic particle

• C) A neutrally charged subatomic particle

• D) A particle with no charge

Answer explanation

An electron is a negatively charged subatomic particle, which distinguishes it from protons (positively charged) and neutrons (neutral). Therefore, the correct answer is B.

Tags

NGSS.MS-PS1-1

Fill in the blank: The atomic number is the number of _______ in the nucleus of an atom, which determines the element's identity.

Answer explanation

The atomic number is defined as the number of protons in the nucleus of an atom. This number uniquely identifies the element, as each element has a distinct number of protons.

Tags

NGSS.MS-PS1-1

Fill in the blank: The atomic mass is the mass of an atom, which is approximately equal to the number of _______ and _______ in the nucleus.

Answer explanation

The atomic mass of an atom is primarily determined by the number of protons and neutrons in its nucleus. Therefore, the correct answer to fill in the blanks is 'protons' and 'neutrons'.

Tags

NGSS.MS-PS1-1

What is a valence electron?

Answer explanation

A valence electron refers to the electrons located in the outermost energy level of an atom. These electrons play a crucial role in chemical bonding, determining how atoms interact with each other.

What is an energy level (shell) in an atom?

(a)  

• A region of an atom where electrons orbit the nucl
• I have no idea.
• I do not pay attention in science. 

Answer explanation

An energy level, or shell, in an atom is a region where electrons orbit the nucleus at a specific energy. This defines the allowed energy states for electrons, making the statement in the answer choice correct.