State the relative mass and charge of a neutron.

Relative mass 1, relative charge 0.

State the relative mass and charge of an electron.

Relative mass about 1/1840 (negligible), relative charge −1.

Define atomic (proton) number.

The number of protons in the nucleus of an atom.

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

Atoms of the same element with the same number of protons but different numbers of neutrons.

Why do isotopes of an element have the same chemical properties?

They have the same number and arrangement of electrons.

Give a physical property that differs between isotopes.

Density or rate of diffusion (anything that depends on mass).

How many protons, neutrons and electrons are in ²⁷Al³⁺ (Z = 13)?

13 protons, 14 neutrons, 10 electrons.

Atomic structure and isotopesEdexcel A-Level Chemistry: Flashcards

Card 1 of 120 of 12 known

Question

State the relative mass and charge of a proton.

Tap or press Space to reveal

Tap card or press Space to flip

See all 12 cards

State the relative mass and charge of a proton.: Relative mass 1, relative charge +1.
State the relative mass and charge of a neutron.: Relative mass 1, relative charge 0.
State the relative mass and charge of an electron.: Relative mass about 1/1840 (negligible), relative charge −1.
Define atomic (proton) number.: The number of protons in the nucleus of an atom.
Define mass number.: The total number of protons and neutrons in the nucleus of an atom.
How do you find the number of neutrons?: Mass number − atomic number.
How many electrons are in an ion of charge 2−?: Atomic number + 2.
How many electrons are in an ion of charge 3+?: Atomic number − 3.
Define isotopes.: Atoms of the same element with the same number of protons but different numbers of neutrons.
Why do isotopes of an element have the same chemical properties?: They have the same number and arrangement of electrons.
Give a physical property that differs between isotopes.: Density or rate of diffusion (anything that depends on mass).
How many protons, neutrons and electrons are in ²⁷Al³⁺ (Z = 13)?: 13 protons, 14 neutrons, 10 electrons.

Exam questions on Atomic structure and isotopes

Sulfur has several naturally occurring isotopes, including ³²S and ³⁴S (atomic number 16). A technician is studying a sample of sodium sulfide, which contains the sulfide ion ³⁴S²⁻.
Explain why ³²S and ³⁴S have the same chemical properties but different masses.2 marks
A physics teacher describes the sodium ion ²³Na⁺ (atomic number 11) to a class using the relative mass and relative charge of the three sub-atomic particles.
Deduce the total relative charge of the ²³Na⁺ ion and its approximate relative mass. Explain why the electrons can be ignored when finding the relative mass.2 marks
Chlorine exists naturally as two isotopes, ³⁵Cl and ³⁷Cl (atomic number 17). A student studies the chloride ion ³⁷Cl⁻ and a chlorine molecule in which one atom is ³⁵Cl and the other is ³⁷Cl.
State the number of protons, neutrons and electrons in one ³⁷Cl⁻ ion.3 marks

See the full worksheet

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).