3.1.1.2 Mass number and isotopes- Isotopes

Question 1

Definition: isotopes

Answer 1

(atoms with the) same number of protons / same atomic number / atoms of the same element
But different number of neutrons / different mass number

Question 2

Difference in the chemical properties of isotopes of the same element

Answer 2

no difference;

same e– arrangement / same number of e– / same valence e– .

Question 3

why atoms of the same element may have different mass numbers

Answer 3

different number of neutrons

Question 4

Definition: mass number of an isotope

Answer 4

Number of protons & number of neutrons

Question 5

Definition: isotopes

Answer 5

Atoms/isotopes/particles/species with the same (number of) protons and 1 different (number of) neutrons

Question 6

Definition: relative isotopic abundance

Answer 6

proportion / ratio / frequency / percentage / abundance of each isotope / different type of atom / specific atom

Question 7

explain the relationship between two isotopes of the same element

Answer 7

Isotopes have the same number of protons

different number of neutrons

Question 8

An element exists as a mixture of three isotopes. Explain, in detail, how the relative atomic mass of this element can be calculated from data obtained from the mass spectrum of the element.

Answer 8

Spectrum gives (relative) abundance
And m/z
Multiply m/z by relative abundance for each isotope
Sum these values
Divide by the sum of the relative abundances

Question 9

differences and similarities in the atomic structure of the isotopes of an element

Answer 9

Differ in mass number or number of neutrons Same proton / atomic number
Isotopes have the same chemical properties
because all have the same electron configuration or number of electrons or same number of valence electrons (so no chemical difference)

Question 10

Account for the existence of isotopes

Answer 10

isotopes have the same atomic number (or same number of protons or same element)
but different number of neutrons (or mass number)

Question 11

Definition: isotopes

Answer 11

Atoms with the same number of protons / proton number

with different numbers of neutrons

Question 12

why isotopes of the same element have the same chemical properties

Answer 12

Chemical properties depend on the number or amount of (outer) electrons (1) OR, isotopes have the same electron configuration / same number of e

Question 13

why atoms of an element may have different mass numbers

Answer 13

They may have different numbers of neutrons