Science 9 - Chapter 1 Test Flashcards
Physical properties of matter
Characteristics of matter that can be observed or measured. Characters that can be observed are called qualitative properties. Character that can be measured are called quantitative properties
Set of properties
The set of properties that a particular substance has is unique. No other substance has that same set of properties. Thus, unknown sentences can be identified by the set of properties they have.
Qualitative
colour lustre - shiny vs matte state - particular temperature ductile - can be pulled into wire malleable - change shape (hammered)
Quantitative
density melting/freezing point boiling/condensation point viscosity - thickness of liquid conductivity- how well it conducts electricity
Compounds and atoms
Compounds are created when atoms of different elements join to form compound atoms. In a compound, all the compound atoms are alike. (We now call Dalton’s compound atoms molecules.)
Atoms cannot be ______
Created or destroyed
Plum pudding model
The “plum pudding” model has the atom as a positively charged sphere, with the electrons evenly distributed on the surface
Dalton’s atomic theory
- all matter is made of atoms which are particles too small to see
- each element has its own kind of atom, atoms of the same element have the same size and mass. Atoms of different elements have different sizes and different masses
- compounds are created when atoms of different elements join to form compound atoms. in a compound, all the compound atoms are alike. (we now call Dalton’s compound atoms molecules)
- Atoms cannot be created or destroyed
What is matter made of?
All matter is made of atoms, which are particles too small to see
Rutherford’s model
Ernest Rutherford’s gold foil experiment led him to propose a nuclear atom, where there was a heavy nucleus in the center, with the electrons occupying the outer areas of the atom.
Atom size
Smallest particle of an element, but are not the smallest particles
Who was a plum pudding model proposed by?
J.J. Thompson proposed the “plum pudding” model
Numbers of particles in atoms
Protons = atomic number
electrons = atomic number (in a neutral atom)
atomic mass = average mass of an element
mass number = protons = neutron*
neutrons = mass number - atomic number
*If you are not told anything else you could make a reasonable guess at a mass number by taking the atomic mass and rounding it to the nearest whole number
Elements and atoms
Each element has its own kind of Atom. Atoms of the same element have the same size and mass. Atoms of different elements have different sizes and masses.
When do chemical changes occur?
When starting materials (reactants) are changed into different materials (products.)
The products will have different properties than the reactants.
Chemical changes occur during chemical reactions.
Difference between chemical change and physical change
Chemical changes change something on a molecular level whereas physical changes rearrange molecules but don’t affect the internal structure
Define the term “Physical Changes”
Physical changes only include changes of state. New materials are not formed. The process is reversible and you can always get back to the original material in the original state.
Give some examples of chemical changes
paper ➡️ ash
raw egg ➡️ cooked egg
potassium ➡️ water ➡️ potassium hydroxide & hydrogen
(One-way arrows show the processes are not reversible)
Give some examples of physical changes
ice ↔️ water
steam ↔️ water
dry ice ↔️ carbon dioxide gas
(Two way symbols show that processes are reversible)
Does irreversibility (not being able to get back to the original reactants) indicate a chemical change?
No, it is not evidence of a chemical change
Define the term “Chemical Changes”
New materials are formed and you cannot go back to the original matter in the original states.
Does a change of state indicate that a chemical reaction has occurred
No
When do chemical reactions occur?
When reactant particles break bonds and rearrange their particles and form new particles.
Evidence chemical reaction
- Heat or light is produced/absorbed
- A colour change occurs
- A new material is formed
- Some original material is used up
- Bubbles appear (new gas forming)
- Cloudiness appears (new solid forming)
Why is the nucleus positively charged?
All the protons are in the nucleus
Electron/Electron Shell
Negative charge {-1}
No mass
Occupies most of the volume of an atom
Proton
Positive charge {+1}
1836 mass
Nucleus
Is tiny (one ten thousandth the size of the rest of the atom)
positively charged
has most of the mass of an atom (protons and neutrons)
Center of an atom
Protons and neutrons not easily removed
Atoms
Basic units of matter
Made of particles (neutron,electron,proton)
Equal number of protons and electrons =
No charge
Neutron
Neutral charge {0}
1837 mass (most massive)Melting point of water? Freezing point of water? Boiling point of water?
0 degrees Celsius
0 degrees Celsius
100 degrees Celsius
Which two subatomic particles exist together in a nucleus?
Protons and neutrons
Is the electron shell negative or positive?
Negative
Location of: proton, neutron, electron
Proton = nucleus Neutron = nucleus Electron = shell outside of nucleus
Matter
Matter is anything that has mass and volume
density
Unit that relates mass and volume
Measure mass?
Grams, kilograms, tonnes, micrograms
Volume
Volume is “how much space” material takes up
Mass
Mass is “how much stuff” there is
How to figure out density?
Dividing mass by volume
Matter can be divided into what?
Substances and mixtures
Measure volume?
Cubic metres (dry things and regular objects) Litres (liquids and irregular objects)
Give some examples of a solution
Tea with lemon, windex, kool aid, coke/Pepsi
What are mixtures made of?
Two or more kinds of particles
What are compounds?
Compounds are pure substances composed of 2 or more elements
How can you tell if something is a mechanical mixture?
In a mechanical mixture, you can see the individual components.
Give some examples of suspension
Smoothie, cappuccino, tea with milk
How can you tell if something is a solution?
In a solution, particles are dissolved in a liquid
True or false. Emotions are matter
False
Give some examples of compounds
Water, sugar, table salt, carbon dioxide
Matter can be _______ into substances and mixtures
Divided
What are elements?
Pure substances that cannot be broken down into simpler substances.
Give some examples of substances
Water, salt, chlorine, nickel, carbon dioxide
Give some examples of elements
Gold, copper, carbon, oxygen, and nitrogen
What types of mixtures are there?
Mechanical mixtures, suspensions, or solutions
Is wave-light matter?
No
What are substances made of?
One kind of matter or one kind of particle. All the particles of a particular type of substance are all the same.
How can you tell if something is a suspension?
In a suspension, solid particles are held in a liquid.
Substances can be ________ or __________.
Elements or compounds
Describe a gas
In a gas, there is a lot of kinetic energy, so there is a lot of movement of the particles. There is a lot of space between particles and a very low density.
Describe a liquid
In a liquid, there is a bit more kinetic energy, so there is very little movement of the particles. This means there are very small spaces between particles, resulting in a very high density.
Describe a solid
In a solid there is very little kinetic energy, so there is little movement of the particles. This means there are very small spaces between particles, resulting in a very high density.
What is the kinetic molecular theory?
This theory explains the behaviour of matter. It suggests that all matter consists of very small particles in constant motion.
What are the states of matter?
Solid, Liquid, Gas
