Chem Unit 5😔 Flashcards
What is an element?
A compound is a substance made from two __ chemically joined together.
A mixture consists of two or more __ and/or compounds which have not been ___ joined together.
- A substance that cannot be broken down any further by chemical changes. Only one kind of atom.
- Elements
- Elements, chemically
State at room temperature and pressure of metals and non-metals.
Metals: Solid( Except mercury-liquid)
Non-metals: Few solid, many gases
Melting point and boiling point of metals and nonmetals .
Metals: Usually high
Nonmetals: Often low
Appearance of metals and nonmetals.
Metals: shiny
Nonmetals: dull
Conduction of electricity and heat of metals and nonmetals.
Metals: good
Nonmetals: poor( except graphite-conductor)
Flexibility and strength of metals and nonmetals.
Metals: malleable, ductile and hard
Nonmetals: brittle if solid
What do atoms consist of?
Which atom doesn’t consist of them?
- 3 smaller sub-atomic particles: protons, neutrons and electrons.
- Hydrogen doesn’t have neutrons.
Protons are __ charged and have a relative mass of ___.
Electrons are ___ charged and have a relative mass of ___.
- Positive, 1
- Negative, 1/1840
The atomic number is the number of ___ in an atom.
Different _____ have different atomic numbers.
- Protons
- Elements
Mass number is the number of ___+___ of an atom.
Is the mass number on top of atomic number or the other way round?
- Protons, neutrons
- Mass on top of atomic number
What are isotopes?
Atoms of a particular element which have the same number of protons but different number of neutrons.
What is the relative isotopic mass?
What is its unit?
- Mass number
- a.m.u. (atomic mass unit)
How can we calculate how much an electron shell can hold?
2(no of electron shell)^2
Which two atoms only have 8 electrons go into the third shell?
Calcium and potassium.
