P1 - 1.2 Elements, Isotopes and Relative Atomic Mass

Question 1

What is an element?

Answer 1

A substance that cannot be broken down into simpler substances and is made up of only one type of atom.

Question 2

What is an isotope?

Answer 2

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

Question 3

True or False: All isotopes of an element have the same chemical properties.

Answer 3

True.

Question 4

What is relative atomic mass?

Answer 4

The weighted average mass of an atom of an element compared to 1/12th of the mass of a carbon-12 atom.

Question 5

Fill in the blank: The relative atomic mass is a __________ average.

Answer 5

weighted.

Question 6

What does the atomic number represent?

Answer 6

The number of protons in an atom.

Question 7

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

Answer 7

Subtract the atomic number from the mass number.

Question 8

Multiple choice: Which of the following is NOT an isotope of Carbon? A) Carbon-12 B) Carbon-14 C) Carbon-15 D) Oxygen-16

Answer 8

D) Oxygen-16.

Question 9

What is the mass number of an atom?

Answer 9

The total number of protons and neutrons in the nucleus.

Question 10

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

Answer 10

True.

Question 11

What is the significance of relative atomic mass in the periodic table?

Answer 11

It helps determine the average mass of an element’s isotopes found in nature.

Question 12

Fill in the blank: Isotopes can be __________ or __________ depending on their stability.

Answer 12

stable; unstable.

Question 13

What is the term for the process by which unstable isotopes decay?

Answer 13

Radioactive decay.

Question 14

Multiple choice: Which isotope of Hydrogen is the most abundant? A) Deuterium B) Tritium C) Protium D) Hydrogen-1

Answer 14

C) Protium.

Question 15

What is the relative atomic mass of Carbon if it has isotopes Carbon-12 and Carbon-14?

Answer 15

Approximately 12.01.

Question 16

What are the three main types of isotopes?

Answer 16

Stable isotopes, radioactive isotopes, and synthetic isotopes.

Question 17

Fill in the blank: The __________ of an element is often used in calculations involving moles.

Answer 17

molar mass.

Question 18

True or False: The chemical behavior of isotopes is identical.

Answer 18

True.

Question 19

What is the primary use of isotopes in medicine?

Answer 19

Diagnosis and treatment of diseases, such as cancer.

Question 20

Multiple choice: Which of these elements has the atomic number 8? A) Nitrogen B) Oxygen C) Carbon D) Helium

Answer 20

B) Oxygen.

Question 21

What does the term ‘nucleon’ refer to?

Answer 21

Protons and neutrons in the nucleus of an atom.

Question 22

Fill in the blank: The average relative atomic mass of an element takes into account the __________ of its isotopes.

Answer 22

abundance.

Question 23

What is the formula for calculating the relative atomic mass from isotopes?

Answer 23

Sum of (isotope mass x fractional abundance) for all isotopes.

Question 24

True or False: Isotopes of the same element can have different physical properties.

Answer 24

True.

Question 25

What is a common application of stable isotopes in research?

Answer 25

Tracing chemical pathways in biological systems.

Question 26

Multiple choice: Which isotope of Uranium is commonly used in nuclear reactors? A) Uranium-235 B) Uranium-238 C) Uranium-234 D) Uranium-239

Answer 26

A) Uranium-235.

Question 27

What distinguishes a synthetic isotope from a natural isotope?

Answer 27

Synthetic isotopes are artificially created in laboratories.

Question 28

Fill in the blank: The __________ of an isotope determines its stability.

Answer 28

neutron-to-proton ratio.

Question 29

What type of decay does Carbon-14 undergo?

Answer 29

Beta decay.

Question 30

True or False: Isotopes with a higher number of neutrons tend to be more stable.

Answer 30

False.

Question 31

What is the role of isotopes in carbon dating?

Answer 31

To estimate the age of organic materials based on the decay of Carbon-14.

Question 32

Multiple choice: Which element has the highest number of stable isotopes? A) Tin B) Lead C) Gold D) Uranium

Answer 32

A) Tin.

Question 33

What is the main difference between atomic mass and relative atomic mass?

Answer 33

Atomic mass is the mass of a specific isotope, while relative atomic mass is the average based on isotopic distribution.

Question 34

Fill in the blank: The __________ of an atom contains protons and neutrons.

Answer 34

nucleus.

Question 35

What is a common method for determining the relative atomic mass of an element?

Answer 35

Mass spectrometry.

Question 36

True or False: The relative atomic mass can be a whole number.

Answer 36

False.

Question 37

What term describes the time it takes for half of a radioactive isotope to decay?

Answer 37

Half-life.

Question 38

Multiple choice: Which of the following is a characteristic of radioactive isotopes? A) They are always stable B) They emit radiation C) They have a fixed mass number D) They cannot be used in medicine

Answer 38

B) They emit radiation.

Question 39

What is the significance of the atomic mass unit (amu)?

Answer 39

It is a standard unit of mass used to express atomic and molecular weights.

Question 40

Fill in the blank: The __________ of isotopes can be used to determine the age of rocks and fossils.

Answer 40

radioactive decay.

Question 41

True or False: Isotopes have different chemical reactivities.

Answer 41

False.

Question 42

What is the main feature that defines a molecule?

Answer 42

A group of two or more atoms bonded together.

Question 43

Multiple choice: Which of the following is an example of an isotope? A) O2 B) H2O C) Carbon-12 D) NaCl

Answer 43

C) Carbon-12.

Question 44

What does the term 'isotopic abundance' refer to?

Answer 44

The relative proportion of each isotope of an element in a sample.

Question 45

Fill in the blank: The __________ of an element can affect its physical properties, such as density.

Answer 45

isotopic composition.

Question 46

True or False: The number of protons in an atom determines its identity as an element.

Answer 46

True.

Question 47

What is the relationship between mass number and atomic number?

Answer 47

Mass number = number of protons + number of neutrons.

Question 48

Multiple choice: Which of the following statements is true about isotopes? A) They always have the same mass number B) They can have different physical properties C) They cannot be used in scientific research D) They always have the same number of neutrons

Answer 48

B) They can have different physical properties.