Chemistry Flashcards
Define- chemical change
When a new substance forms during a chemical reactions and cannot be easily reversed.
Define- physical change
A change of state, between solid, liquid and gas and no new substance is formed (can be easily reversed)
Define- atom
Smallest particle of an element
Define- periodic table
Table is which all of the known elements are arranged
Define- atomic number
Number of protons/electrons in an atom
Define- malleable
Property of a metal- can be shaped
Define- density
The mass of a substance divided by it’s volume to determine how close the particles inside are
What is density measured in?
g/cm3 or kg/L
Define- conductor
Property of a metal that can let electricity and heat through it easily
Define- mass number
Number of protons plus neutrons in the nucleus of an atom
Define- proton
The positively charged particle found in the nucleus of the atom
Define- neutron
The neutral particle found in the nucleus of an atom
Define- electron
The negatively charged particle, with no mass, found in the orbitals surrounding the nucleus.
Define- ion
An atom or molecule that has gained or lost electrons to form a full valence shell and become stable.
Define- reactant
A substance that takes part in, or gets changed in a chemical reaction. Appears on the left in a word or symbol equation)
Define- product
The substances that form during a chemical reaction (appears on the right in a word or symbol equation)
Define- valence shell
The outermost orbital of an atom
Distinguish between where metals and non-metals are located on the periodic table
The nonmetals are located on the upper right side of the periodic table. The metals are located on the left side.
What properties do all metals share?
Lustrous, malleable, ductile and electrical conductors
What are the columns called?
Groups
What are the rows called?
Periods
What do atoms in the same GROUP have?
The same number of valence electrons
What do atoms in the same PERIOD have?
The same number of electron shells
Why are atoms in group 18 called noble gases?
They have full valence shells so can’t form ions or compounds
What does the electron arrangement show?
The electron arrangement shows how many electrons are on each shell
Why are atoms neutral overall?
Atoms are neutral overall because the total number of negatively charged electrons is the same as the number of positively charged protons so they cancel each other out
What do word equations show?
Word equations show what has happened in a reaction
What happens if an atom loses electrons?
It forms a positive charged ion
What happens if an atom gains electrons?
It forms a negative charged ion
Why are ionic compounds neutral overall?
The positive and negative charges of the ions cancel each other out
What are some observations you would see during a chemical reaction?
Colour change, fizzing/bubbles meaning gas is being produced, heat or light is produced, burning anything (a reaction to oxygen)
What are some observations you would see during a physical reaction?
A change of shape, a change of state, dissolving
Compare and contrast a physical/chemical change
A physical change is easy to reverse whereas chemical reactions are not. Physical changes can include a change of state or shape while chemical changes can include a change of colour. In both chemical and physical changes, the atoms/elements will stay the same, and a change of density could happen.
