Chemistry Chapter 4 Flashcards
Physical properties
Is a characteristic that you can measure or observe without changing the chemical make-up of the matter.
How to observe physical properties
- you can observe with the 5 senses
- you can measure, like using a thermometer to measure temperature.
Physical properties examples
- states of matter
- hardness
- malleability
- ductility
- metaling and boiling points
- crystal form
- solubility
- viscosity
- density
Chemical properties
Describe how a substance behaves during a chemical reaction
How to observe chemical properties
A substance has to change its make-up for us to the chemical properties.
Chemical properties examples
- flammability
- toxicity
- acidity
- heat of combustion
Physical changes
Are those in which the shape,size or state of the matter changes but the substance is will the same.
Chemical changes
You end up with something very different than what you started with. Like mixing chemicals
Chemical changes hints
- new color
- heat or light given off
- bubbles or gas formed
- a solid material forms into a liquid
- difficult to reverse
Matter classification
- pure substance
- mixtures
Pure substances
- Elements: cannot be broken down
- Compounds: 2 atoms together
Mixtures
- Homogeneous (solution): 1 phase (Apple juice or coffee
- Heterogeneous (mechanical mix.): 2 or more phases (pizza or vinaigrette)
Antoine Lavoisier
Was the father of chemistry b/c he recognized that oxygen is an element and is important in playing sorts in different chemical reaction.
Antoine Lavoisier oxygen expirement
When he heated mercury oxide, the chemicals weight decreased was equal to the gas released.
Democritus (Atomic theory)
- proposed that the world is made out of tiny particles that are in constant motion, are different sizes and are separated by empty space.
- no once accept this theory, every one believed in earth, water, air and fire theory (lasted for 2000 years)
John Dalton (Atomic theory)
- billiard ball model
- all atoms are small and invisible
- all atoms of the same element ate the same, different element have different atoms.
Atoms can be rearranged to form new substances in chemicals reactions but the can neither be created or destroyed.
J.J Thompson (Atomic theory)
- the rain bun model
- atoms contain electrons
- the rest of the atom is positively charged cloud with electron evenly distributed throughout
Ernest Rutherford (Atomic theory) gold foil experiment
Rutherford shot positive charges at a gold foil expecting to go through, instead some bounced back
Ernest Rutherford discovered
- the nucleus is a dense positive charge (protons and neutrons)
- the nucleus is surrounded by by a cloud of electrons
- most of the atom is empty space
Neils Bohr (Atomic theory)
- electrons go around the nucleus at fixed points in different orbits.
- 2, 8, 8, 18
James Chadwick (Atomic theory)
- discovered neutrons that are found in nucleus
- they have no charge
- electrons circle through the empty space around the nucleus
What is in an atom?
- Protons ( weight 2000x more than e- )
- Neutrons ( weight 2000x more than e- )
- Electrons ( very light )
Atomic mass
Total number neutrons and protons
Mass number
The total amount of protons and the total amount of neutrons.
Atomic numbers
The number of protons
Atomic numbers
The number of protons
How many element in the periodic table
The are 92 natural elements ( 118 total )
Particle theory
- matter is made up of tiny particles
- all particles of matter are separated by empty space
- all atoms of the same element are the same and all atoms of different elements are different.
- are particles of matter are attracted to each other
- all particles of matter are separated by empty space.
Main parts of the table
- metals
- non-metals
- metalloids
Metal properties
- lustre
- malleability
- ductility
- good conductors
- solids
Symbol of staircase line in P-table
Symbolise the metalloids and separates the metals and non-metals
Non-metals properties
- dull
- not malleable
- not ductile
- poor conductors
- solid, liquid, gas
Metalloids properties
Both properties of non-metals and metals
Chemicals family
- Alkali metals
- Alkaline Earth metals
- Halogens
- Noble gases
- Transition metals
Alkali metals
- reactive
- give away 1 valence electron
- positive 1 charge
Alkaline Earth metals
- reactive
- give away 2 valence electrons
- have a positive 2 charge
Halogens
- most reactive
- want electrons
- has a negative 1 charge
Noble gases
- least reactive
- their out shells are full, they have all valence electrons
- have a charge of 0
Transition metals
- toxic
- dense
- conductive
- ductile
What is a charged atom
An ion
Ions
- Cations: positive charged ions = lost on electrons
- Anions: negatively charged ion = got in electrons
Compounds
- Ionic compound
- Molecular / covalent compounds
Ionic compounds
Forms when a metal reacts with a non-metal. Made up of charged particles called ions
Molecular / covalent compounds
Are molecules that are made up of 2 or more different elements, they from when non-metals react with non-metals.
Molecule
Is a small particles of a pure substance that has 1 or more shared electrons.
Molecular element
Is a pure substance made of 2 or more of the same atom
Chemical bonds
A chemical link between two or more atoms
Ionic bond
A bond that forms between oppositely charged atoms (cations and anions)
Covalent/ molecular bond
Is when one or more electrons are being shared between atoms
How atoms make light
When energy is shot at an electron it jumps form its ground state to its exited state absorbing energy. This is brief and goes back to its ground state releasing the energy producing light.
Ball and stick models
This model helps show how the atoms in a molecule are arranged in three demential space.
Space filling model
Is a more accurate presentation of the sizes of the molecule.
