Grade 9 Chem Flashcards
What is the difference between a Physical Change and a Chemical Change?
A physical change in a substance doesn’t change what the substance is, it changes the physical properties. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
What is the difference between Physical Properties and Chemical Properties?
A physical property is an aspect of matter that can be observed or measured without changing it. A chemical property may only be observed by changing the chemical identity of a substance. This property measures the potential for undergoing a chemical change.
Amount of matter per unit volume of a substance
Density
Solid, liquid, gas
States of matter
Solid: lots of attraction,
Ability of a substance to be hammered or bent into different shapes
Malleability
Ability of a substance to dissolve in a solvent
Solubility
Ability of a substance to be pulled into a wire
Ductility
Describes how thick a liquid is/ability of a liquid to flow
Viscosity
Describes how much light can pass through a substance
Luminance
Describes how shiny a substance is
Lustre
A measure of a substance’s resistance to being scratched/dented
Hardness
The shape of the particles of a solid
Cube-like, attracted to one another a lot
Sawing wood
Physical change: the object is still wood, it’s just cut in half
Boiling water
Physical change: the water only has heat added, it’s still the same water, but just in a different state of matter (maybe)
Burning magnesium
Chemical change: The oxygen in the flame mixes with the magnesium to make magnesium oxide, a new substance
Cutting vegetables
Physical change: the object is still vegetables, they’re just cut in half
Car rusting
Chemical change: the moisture, the metal, and the oxygen are mixed together, energy is transferred, and a new substance is made
Baking a cake
Physical the Chemical change: pouring the batter with the water is just changing the appearance of the batter. The baking part, the components react to the heat which expands the elements and makes the outside harder
Ice melting
Physical change: The substance is not being mixed with anything other than heat, the state of matter is only changed
Solid
Close together, vibrates, very attracted
Liquid
Kind of close together, moves around more than a solid, less attracted than solid
Gas
Far apart, moves randomly, not attracted at all
Magnesium properties
very lustrous, precipitates when mixed with water (powder), malleable
Chemical change signs CPHGOTN
Color change, bubbles of gas are formed, a precipitate (solid) forms, heat or light is given off (or heat is taken in), change in odor, taste, new substance
A clear colorless liquid is split into two different gases. The clear colorless liquid can be classified as a ______________________ because it is made of _____________ or more different elements. The two gases are classified as ______________________ because they cannot be _____________________ down into smaller substances. The liquid is most likely ____________ and the two gases that make up the liquid are ____________________ and _____________________.
A clear colorless liquid is split into two different gases. The clear colorless liquid can be classified as a compound because it is made of two or more different elements. The two gases are classified as elements because they cannot be broken down into smaller substances. The liquid is most likely water and the two gases that make up the liquid are hydrogen and oxygen.
How would you test for the presence of oxygen or hydrogen?
Use either a glowing splint or a lit splint and place it in the test tube. If the gas is oxygen (glowing splint) the splint will ignite. If the gas id hydrogen (lit splint) a pop sound will occur ant the splint will suddenly get brighter then fade out.
How would you test for the presence of carbon dioxide?
A lit splint flame is immediately extinguished
Group
A bunch of elements on the periodic table that are in the same column that have similar characteristics
Period
A bunch of elements on the periodic table that are in the same row and have the same number of electron shells. The period number is the number of electron shells that element has.
CH4
Carbon tetrahydride
Ammonia
NH3
Physical change signs
Change of state, change of size, change of colour
Pure substance
Only has one type of particle, could be a compound
Heterogenous vs. Homogenous
Hetero: can see different particles in the mixture
Homo: can’t see different particles in mixture
Solution
Homo mixture (can’t see different particles)
Alloy
Solution of a metal and another element
Molecule
Group of 2 or more atoms held together by chemical bonds
Compound
Made up of molecules. Smallest component is a molecule (eg. H2O)
Bohr-Rutherford diagram
Nucleus contains protons and neutrons, electrons following the outer circle contains electrons. (2,8,8,18)
Atomic mass
Average mass of all isotopes of that element
Atomic number
Rounded atomic mass. Number of protons and electrons
Alkali metals
Far left, very reactive
Alkaline earth metals
Second left, kind of reactive
Halogens
Second right, most reactive non-metals
Noble gases
Far right, very stable
Middle of the table
Transition metals
Binary compound
Two elements only, has to me a metal and non-metal (eg. NaCl - Sodium chloride)
