C2.1 Flashcards
What is the difference between elements, compounds, and mixtures?
Elements are pure substances made of one type of atom, compounds are substances formed from two or more elements chemically bonded, and mixtures are combinations of two or more substances that are not chemically bonded.
Describe the structure of the atom.
An atom consists of a central nucleus containing neutrons and protons, surrounded by electrons in shells.
What are the relative charges and relative masses of a proton, a neutron, and an electron?
Proton: charge +1, mass 1; Neutron: charge 0, mass 1; Electron: charge -1, mass ~0.
Define proton number / atomic number.
The proton number / atomic number is the number of protons in the nucleus of an atom.
Define mass number / nucleon number.
The mass number / nucleon number is the total number of protons and neutrons in the nucleus of an atom.
State a characteristic of Group VIII noble gases.
Group VIII noble gases have a full outer shell.
What is the relationship between the number of outer-shell electrons and the group number in Groups I to VIII?
The number of outer-shell electrons is equal to the group number.
What does the period number indicate about an atom?
The number of occupied electron shells is equal to the period number.
Define isotopes.
Isotopes are different atoms of the same element that have the same number of protons but different numbers of neutrons.
True or False: Isotopes of the same element have different chemical properties.
False.
Why do isotopes of the same element have the same chemical properties?
Because they have the same number of electrons and therefore the same electronic configuration.
