atomi e molecole

Question 1

What is the smallest unit of an element?

Answer 1

An atom.

Question 2

True or False: Protons have a negative charge.

Answer 2

False.

Question 3

What particles are found in the nucleus of an atom?

Answer 3

Protons and neutrons.

Question 4

Fill in the blank: The number of protons in an atom determines its ______.

Answer 4

atomic number.

Question 5

What is the charge of an electron?

Answer 5

Negative.

Question 6

How many protons does a carbon atom have?

Answer 6

6 protons.

Question 7

Multiple Choice: Which particle has a positive charge? A) Electron B) Proton C) Neutron

Answer 7

B) Proton.

Question 8

True or False: Molecules are made up of two or more atoms bonded together.

Answer 8

True.

Question 9

What is the term for atoms of the same element with different numbers of neutrons?

Answer 9

Isotopes.

Question 10

Fill in the blank: The mass number of an atom is the sum of ______ and ______.

Answer 10

protons; neutrons.

Question 11

What is the chemical symbol for oxygen?

Answer 11

O.

Question 12

Multiple Choice: Which of the following is a molecule? A) O2 B) He C) Na

Answer 12

A) O2.

Question 13

What is an ion?

Answer 13

An atom or molecule with a net electric charge due to the loss or gain of one or more electrons.

Question 14

True or False: Neutrons have no charge.

Answer 14

True.

Question 15

What determines the chemical properties of an element?

Answer 15

The arrangement of electrons.

Question 16

Fill in the blank: The outermost electrons of an atom are called ______ electrons.

Answer 16

valence.

Question 17

What is the difference between an atom and a molecule?

Answer 17

An atom is a single unit of an element; a molecule is two or more atoms bonded together.

Question 18

Multiple Choice: Which of the following particles is not found in the nucleus? A) Neutron B) Proton C) Electron

Answer 18

C) Electron.

Question 19

What is the atomic number of hydrogen?

Answer 19

1.

Question 20

True or False: All atoms of a given element have the same number of electrons.

Answer 20

True.

Question 21

Fill in the blank: The strong nuclear force holds ______ together in the nucleus.

Answer 21

protons and neutrons.

Question 22

What is a covalent bond?

Answer 22

A chemical bond formed by the sharing of electrons between atoms.

Question 23

What is the primary component of water?

Answer 23

H2O (two hydrogen atoms and one oxygen atom).

Question 24

Multiple Choice: Which particle is responsible for the chemical behavior of an atom? A) Proton B) Neutron C) Electron

Answer 24

C) Electron.

Question 25

What does the term 'molecular formula' describe?

Answer 25

The number and type of atoms in a molecule.

Question 26

True or False: The mass number is always greater than the atomic number.

Answer 26

True.

Question 27

Fill in the blank: Atoms are primarily made up of ______ space.

Answer 27

empty.