The fundamental ideas Flashcards
Define matter
The term matter refers to anything that occupies space and has mass.
How many regions is an atom made up of?
Two regions
Atomic nucleus and Electrons
Define atom
An atom is the smallest unit of matter that retains all of the chemical properties of an element. It is made up of smaller fundamental particles. In Greek the prefix a means not and the word tomos means cut. Atom is derived from the greek word atomos meaning uncuttable or meaning indivisible.
Protons, Neutrons and Electrons are all…
sub-atomic particles.
What unit measures the mass of an element?
The dalton or atomic mass unit (amu)
- 66053892 x 10-27 kilograms
- 66053892 × 10-24 grams
What is the relative mass of an electron?
What is an atomic number?
The number of protons in the nucleus of an atom.
What are isotopes?
Isotopes are atoms of a single element that differ only in the number of neutrons in their nuclei. Neutrons have mass therefore isotopes also differ in atomic mass. Hyphen notation is used to show an isotope.
What is a compound?
A compound is a distinct group of atoms held together by chemical bonds.
What is the relative electrical charge for the three sub-atomic particles?
What is the mass of an atom?
The sum of the protons and neutrons in an atom is its mass number.
On the Periodic table, what does the group number tell you?
Elements in the same group in the periodic table have the same number of electrons in their highest energy level (outer electrons) and this gives them similar chemical properties.
What does the period number indiate?
The number of shells/ orbitals.
Describe group 0 of the periodic table
The elements in Group 0 of the periodic table are called the noble gases. They are unreactive because their atoms have stable arrangements of electrons.
Noble gases have eight electrons in their outer energy level, except for helium, which has only two electrons.
A compound is…
two or more different elements that have reacted chemically with each other.
