| The basic units of chemical elements, consisting of a nucleus of protons and neutrons, with electrons orbiting around the nucleus. | Atoms |
| What is an atom's mass number? | An atom's mass number is the sum of its protons and neutrons. |
| The total number of protons and neutrons in an atom's nucleus. | Mass Number |
| What is an atom's atomic number? | An atom's atomic number is the number of protons it has. |
| The number of protons in the nucleus of an atom, which determines its chemical properties and place in the periodic table. | Atomic Number |
| How are atoms represented in terms of their mass number and atomic number? | Atoms are represented by their mass number (total protons and neutrons) and atomic number (number of protons). |
| A tabular arrangement of chemical elements, organized by their atomic number, electron configurations, and recurring chemical properties. | Periodic Table |
| Do atoms of the same element have the same or different atomic numbers? | Atoms of the same element always have the same atomic number (number of protons). |
| Substances consisting of atoms with the same atomic number, characterized by their unique chemical properties. | Elements |
| How do the atomic numbers of atoms of different elements compare? | Atoms of different elements always have different atomic numbers. |
| The total number of protons and neutrons in the nucleus of an atom. | Mass Number |
| What is the relationship between the mass number and the number of protons and neutrons in an atom? | The mass number of an atom is equal to the sum of its protons and neutrons. |
| The number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table. | Atomic Number |
| How is the number of protons determined in an atom? | The atomic number of an atom indicates the number of protons in its nucleus. |
| A chemical element with the atomic number 3 and the symbol Li. | Lithium (Li) |
| How many protons does an atom of lithium have? | An atom of lithium has 3 protons. |
| Neutral subatomic particles found in the nucleus of an atom, with a mass nearly equal to that of protons. | Neutrons |
| How can you calculate the number of neutrons in an atom? | The number of neutrons in an atom can be calculated by subtracting the atomic number (number of protons) from the mass number. |
| Negatively charged subatomic particles that orbit the nucleus of an atom. | Electrons |
| How many electrons does a neutral atom of lithium have? | A neutral atom of lithium has 3 electrons, which equals the number of protons. |
| An atom with an equal number of protons and electrons, resulting in a net charge of zero. | Neutral Atom |
| What determines the number of electrons in a neutral atom? | In a neutral atom, the number of electrons is equal to the number of protons, maintaining electrical neutrality. |
| Atoms of the same element with the same number of protons but different numbers of neutrons. | Isotopes |
| What distinguishes isotopes of the same element from each other? | Isotopes of the same element have different numbers of neutrons. |
| Positively charged subatomic particles found in the nucleus of an atom. | Protons |
| Can isotopes of the same element have different numbers of protons? | No, isotopes of the same element have the same number of protons. |
| Neutral subatomic particles found in the nucleus of an atom, with a mass nearly equal to that of protons. | Neutrons |
| What is the defining characteristic of isotopes? | Isotopes differ in the number of neutrons while having the same number of protons. |
| A stable isotope of carbon with 6 protons and 6 neutrons. | Carbon-12 |
| How many protons and neutrons does carbon-12 have? | Carbon-12 has 6 protons and 6 neutrons. |
| A stable isotope of carbon with 6 protons and 7 neutrons. | Carbon-13 |
| How does the number of neutrons in carbon-13 differ from carbon-12? | Carbon-13 has one more neutron than carbon-12. |
| The sum of the number of protons and neutrons in the nucleus of an atom. | Mass Number |
| How do isotopes of the same element differ in terms of their mass numbers? | Isotopes of the same element have different mass numbers due to varying numbers of neutrons. |
| The average atomic mass of an element, taking into account the abundance of its isotopes. | Relative Atomic Mass |
| What does the relative atomic mass of an element consider? | The relative atomic mass considers the abundance of an element's isotopes. |
| The sum of the number of protons and neutrons in the nucleus of an atom. | Mass Number |
| What information does the mass number shown in the periodic table provide? | The mass number provides the relative atomic mass of an element. |
| Atoms of the same element with the same number of protons but different numbers of neutrons. | Isotopes |
| How does the abundance of isotopes affect the relative atomic mass of an element? | The relative atomic mass is influenced by the abundance of isotopes, with more abundant isotopes contributing more to the average. |
| The most common isotope of carbon, with 6 protons and 6 neutrons. | Carbon-12 |
| Why does carbon-12 contribute significantly to the relative atomic mass of carbon? | Carbon-12 is highly abundant, constituting over 98% of all carbon, which influences carbon's relative atomic mass. |
| An isotope of chlorine with 17 protons and 18 neutrons, constituting about 75% of natural chlorine. | Chlorine-35 |
| How does the abundance of chlorine isotopes affect its relative atomic mass? | The relative atomic mass of chlorine considers the abundance of chlorine-35 and chlorine-37 isotopes. |
| An isotope of chlorine with 17 protons and 20 neutrons, constituting about 25% of natural chlorine. | Chlorine-37 |
| Why is the relative atomic mass of chlorine not a whole number (35.5)? | Chlorine's relative atomic mass is not a whole number because it reflects the average of chlorine-35 and chlorine-37 isotopes, which have different masses. |
| The average atomic mass of an element, considering the abundance of its isotopes. | Relative Atomic Mass (Ar) |
| What does the symbol Ar represent in chemistry? | Ar represents the relative atomic mass of an element. |
| The percentage of each isotope present in a naturally occurring sample of an element. | Percentage (isotope) Abundance |
| How is an element's relative atomic mass calculated if the percentage abundances of its isotopes are known? | The relative atomic mass is calculated by multiplying the mass number of each isotope by its percentage abundance, summing these values, and dividing by 100. |
| A chemical element with symbol Br and atomic number 35. | Bromine |
| What are the two isotopes of bromine and their respective mass numbers? | The isotopes of bromine are bromine-79 (mass number 79) and bromine-81 (mass number 81). |
| An isotope of bromine with a mass number of 79. | Bromine-79 |
| What is the percentage abundance of bromine-79? | The percentage abundance of bromine-79 is 50%. |
| An isotope of bromine with a mass number of 81. | Bromine-81 |
| What is the percentage abundance of bromine-81? | The percentage abundance of bromine-81 is also 50%. |
| The process of determining the relative (average) atomic mass of an element based on the abundance and mass numbers of its isotopes. | Calculation of Relative Atomic Mass |
| How is the relative atomic mass of bromine calculated using the given information? | The relative atomic mass of bromine can be calculated using the formula: Ar = (79 × 0.50) + (81 × 0.50). |
