IGCSE CHEM_CHAP 2.3_Isotopes

Isotopes

Atoms of the same element that have the same number of protons and electrons but different numbers of neutrons; Đồng vị.

Mass number (Nucleon number)

The total number of protons and neutrons in the nucleus of an atom; Số khối.

Atomic number (Proton number)

The number of protons in the nucleus of an atom, which identifies the element; Số hiệu nguyên tử.

Ion

An atom that has gained or lost electrons, resulting in a positive or negative charge; Ion.

Relative atomic mass

An average value that takes into account the abundance of the isotopes of an element; Khối lượng nguyên tử tương đối.

Abundance

The percentage or proportion of a specific isotope found in a natural sample of an element; Độ phổ biến (hàm lượng phần trăm).

Electron configuration

The arrangement of electrons in the shells of an atom or ion; Cấu hình electron.

Isotopes

What are atoms of the same element with the same number of protons but different numbers of neutrons?

Same

Do isotopes of the same element have the same or different numbers of electrons?

Different

Do isotopes of the same element have the same or different mass numbers?

Carbon-12 and Carbon-13

What are two examples of carbon isotopes mentioned in the notes?

12

How many protons does Carbon-13 have?7

6

How many neutrons does Carbon-12 have?

Top

In the Periodic Table, where is the mass number usually written in an element's symbol?

Bottom

In the Periodic Table, where is the atomic number usually written in an element's symbol?

Atomic number

Which number is used to identify the number of protons in an atom?

Mass number minus atomic number

How do you calculate the number of neutrons from an element's symbol?

Ion

What is formed when an atom loses or gains electrons?

It stays the same

What happens to the atomic number when an atom becomes an ion?

It stays the same

What happens to the mass number when an atom becomes an ion?

An electron has been lost

What does a plus (+) symbol after an element's letters indicate?

An electron has been gained

What does a minus (-) symbol after an element's letters indicate?

11

How many protons are in a Na+ ion (atomic number 11)?

10

How many electrons are in a Na+ ion (atomic number 11)?

17

How many protons are in a Cl- ion (atomic number 17)?

18

How many electrons are in a Cl- ion (atomic number 17)?

18

If a Cl- ion has a mass number of 35 and 17 protons, how many neutrons does it have?

They have the same chemical properties

What is true about the chemical behavior of isotopes of the same element?

They have the same number of electrons

Why do isotopes have the same chemical properties?

The electronic configuration stays unchanged

What remains the same in isotopes that determines their chemistry?

Relative atomic mass

What value is calculated using the masses and abundances of all isotopes of an element?

100

What number do you divide by at the end of the relative atomic mass formula?

Isotope mass x abundance

What do you multiply together for each isotope before adding them in the RAM formula?

12.4

What is the RAM of Carbon if it has 20% Carbon-14 and 80% Carbon-12?

Average value

Is relative atomic mass an exact mass of one atom or an average value?

Same

Do isotopes of the same element occupy the same or different positions in the Periodic Table?

35

In the symbol {35}_{17}Cl, what is the mass number?

17

In the symbol {35}_{17}Cl, what is the atomic number?

Mass number

Which number in the symbol A}_{Z}X represents the nucleons?

Atomic number

Which number in the symbol {A}_{Z}X represents the protons?

The number of protons and electrons

What two things are equal in a neutral atom but not in an ion?

Positive charge

What type of charge does an atom have if it loses electrons?

Negative charge

What type of charge does an atom have if it gains electrons?

23

What is the mass number of a Sodium (Na+) ion if it has 11 protons and 12 neutrons?

Protons

Which subatomic particle's number never changes between isotopes of the same element?

Neutrons

Which subatomic particle's number is the only difference between isotopes?

Same

Do isotopes have the same or different electron configurations?

1

How many electrons are gained by an atom with a "-1" charge?

2

How many electrons are lost by an atom with a "+2" charge?

Nucleus

In which part of the atom are the protons and neutrons of an isotope located?

Shells

Where are the electrons of an isotope located?

Abundance

What term describes how common an isotope is in nature?

Sum of (mass x abundance)

What is the numerator in the relative atomic mass equation?

Chemical properties

Which properties are identical for 12 C and 13 C?

Physical properties

Which properties (like density) might differ slightly between isotopes?

Proton number

What is the most important number for determining the identity of an element?