Particles 2

Question 1

What particles are in the central nucleus?

Answer 1

Protons and neutrons

Question 2

What is the size relationship between the nucleus and the atom?

Answer 2

Nucleus is about 10,000 times smaller than the atom.

Question 3

What does the atomic number (Z) represent?

Answer 3

Number of protons in an atom’s nucleus

Question 4

What is the difference between isotopes?

Answer 4

Number of neutrons

Question 5

What is the atomic number of a magnesium atom?

Answer 5

12

Question 6

Do electrons have a larger mass than protons and neutrons?

Answer 6

No, electrons have much smaller mass.

Question 7

How does the atomic number relate to electron count in an atom?

Answer 7

It’s equal to the number of electrons

Question 8

What is an ion?

Answer 8

Electrically charged atom or group of atoms

Question 9

What is the atomic number of a carbon atom?

Answer 9

6

Question 10

What is the size of atoms?

Answer 10

1 x 10-10 metres

Question 11

What does the mass number (A) represent?

Answer 11

Total number of protons and neutrons in an atom’s nucleus

Question 12

What happens when an atom loses electrons?

Answer 12

Positive ion or cation

Question 13

What is the formula to calculate the number of protons?

Answer 13

Number of protons = mass number - number of neutrons

Question 14

Where is most of the atom’s mass concentrated?

Answer 14

Inside the nucleus.

Question 15

How are isotopes of an element different from each other?

Answer 15

Different number of neutrons

Question 16

What happens when an atom gains electrons?

Answer 16

Negative ion or anion

Question 17

How many protons are present in an unknown atom of element X with a mass number of 63 and 34 neutrons?

Answer 17

29

Question 18

Where do electrons move in an atom?

Answer 18

Outside the nucleus in orbits.

Question 19

Why do isotopes exhibit the same chemical characteristics?

Answer 19

They have the same number of electrons

Question 20

How do you calculate the number of neutrons in an atom?

Answer 20

Number of neutrons = mass number (A) - atomic number (Z)

Question 21

How are the masses and charges of subatomic particles often compared?

Answer 21

Relative to each other

Question 22

Why are atoms with incomplete outer electron shells unstable?

Answer 22

Unequal number of protons and electrons

Question 23

What is the atom?

Answer 23

Smallest part retaining properties of element

Question 24

What is the symbol for atomic number?

Answer 24

Z

Question 25

How do atoms become stable?

Answer 25

Gain or lose electrons

Question 26

What is the number of protons in a Mg2+ ion?

Answer 26

12

Question 27

What are the subatomic particles that make up an atom?

Answer 27

Protons, neutrons, electrons

Question 28

Can the proton number of an atom change in a chemical reaction?

Answer 28

No

Question 29

How can you calculate the number of protons in an atom?

Answer 29

Atomic number equals number of protons

Question 30

What is the relative mass assigned to protons and neutrons?

Answer 30

1

Question 31

What is the formula to find the number of neutrons in an atom?

Answer 31

Mass number - atomic number

Question 32

How do you find the number of neutrons in an atom?

Answer 32

Subtract atomic number from mass number

Question 33

How does the mass of electrons compare to protons and neutrons?

Answer 33

Negligible, 1836 times smaller

Question 34

How are isotopes symbolized?

Answer 34

Element’s chemical symbol followed by mass number (e.g., C-14 or 14C)

Question 35

What is the mass number in an atom?

Answer 35

Number of protons plus neutrons

Question 36

Example: What is the atomic number of beryllium and how many protons does it have?

Answer 36

Atomic number of 4, 4 protons