Topic 1 - Atomic Structure And The Periodic Table Flashcards
What does an atom contain?
Protons, neutrons and electrons
How big is the radius of an atom?
About 0.1 nanometers
What are features of the nucleus of an atom?
Its in the middle of the atom. Contains protons and neutrons. Radius of about 1 x 10^-14 Positively charges Where most of the mass of an atom is concentrated.
What are the features of an electron?
Moves around the nucleus in electron shells.
Negatively charged
Volume of their orbit determines the size of the atom.
Have virtually no mass.
Whats the difference between an ion and an atom?
An ion has more/less electrons than protons which then gives itself a charge.
An atom is neutral since the amount of protons and electrons cancel each other out.
Which number on the periodic table is the mass number and atomic number?
Mass number is the bigger number (top)
What does the atomic number tell you?
Amount of protons
What does the mass number tell you?
Total number of protons and neutrons
What is an element?
A substance that only contains atoms with the same atomic number
What is an isotope?
They are different forms of the same element with same number of protons but different number of neutrons. So same atomic number but different mass numbers.
How do you find relative atomic mass? (Ar)
Ar = sum of (isotope abundance x isotope mass number) / sum of all abundances
What is a compound?
Substances formed from 2 or more elements. The atoms of each are in fixed proportions and are held together by chemical bonds.
What are the features of a compound formed from a metal and non metal?
Consists of ions.
Metal loses electrons to form positive ions and non metal gains electrons to form negative ions.
Opposite charges of ions means they strongly attract to each other.
What are the features of a compound formed from 2 non metals?
Consists of molecules.
The atoms share electrons which other atoms (covalent bonding).
Fill in the blanks. Just as elements are represented with _____ , compounds are represented with _____.
1) Symbols
2) Formulas
What is a mixture?
2 or more elements mixed together but the atoms are not chemically bonded.
Eg air is a mixture of gases like oxygen, nitrogen, carbon dioxide and argon.
How can you use filtration to separate a mixture?
Can be used to separate insoluble solids from a liquid.
Can also be used for purification