Atoms and their parts

The atomic number of an element is the same as its...

• number of protons

• number of electrons

• number of neutrons

• number of photons

Answer explanation

The atomic number of an element is defined as the number of protons in its nucleus. This number determines the element's identity and its position in the periodic table, making 'number of protons' the correct answer.

The atomic mass of an atom is

• the number of protons and neutrons

• the amount of electrons

• the number of electrons and protons

• the number of neutrons

Answer explanation

The atomic mass of an atom is determined by the total number of protons and neutrons in its nucleus. Electrons have negligible mass and do not contribute to the atomic mass.

Tags

NGSS.MS-PS1-1

An atom that is a just a single proton is

• hydrogen

• carbon

• oxygen

• neutral

Answer explanation

An atom with just a single proton is hydrogen, the simplest element. Carbon has six protons, oxygen has eight, and 'neutral' refers to charge, not atomic identity.

The number of protons in an atom always equals the number of

• electrons

• neutrons

• elements

• grams

Answer explanation

In a neutral atom, the number of protons equals the number of electrons, ensuring electrical balance. Neutrons can vary, leading to different isotopes, while elements refer to distinct types of atoms.

The number of protons in an atom determines

• what it is

• its total mass

• its isotope

• if it likes cats

Answer explanation

The number of protons in an atom defines its atomic number, which determines the element's identity. Therefore, the correct answer is 'what it is', as it specifies the type of element.

What are electrons responsible for?

• chemical bonding

• chemical mass

• chemical reactivity

• light emission

Answer explanation

Electrons play a crucial role in chemical bonding by forming connections between atoms, influence chemical reactivity by participating in reactions, and are involved in light emission through energy transitions.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

How many electrons does this oxygen atom have?

• 6

• 8

• 10

• 4

Answer explanation

An oxygen atom has 8 electrons, which is equal to its atomic number (8). This is the correct answer, as it reflects the number of protons in the nucleus, determining the electron count in a neutral atom.

Tags

NGSS.HS-PS1-1

How many protons does this atom have?

• 8

• 6

• 4

• 10

Answer explanation

The number of protons in an atom is equal to its atomic number. An atom with 8 protons corresponds to oxygen, which has an atomic number of 8. Therefore, the correct answer is 8.

Tags

NGSS.MS-PS1-1

How many electrons can interact or bond with another atom?

• 6

• 8

• 4

• 2

Answer explanation

The correct answer is 6 because in a typical bonding scenario, atoms can share or transfer up to 6 electrons in their outer shell, allowing for stable interactions with other atoms.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

How many oxygen ATOMS are in this reaction?

• 4

• 6

• 2

• 8

Answer explanation

In the reaction, count the oxygen atoms from the reactants and products. If there are 4 oxygen atoms total, the correct answer is 4.

Tags

NGSS.HS-PS1-7