Chem Flashcards
(26 cards)
What is the particle theory?
- All matter consists of extremely small particles
2.All particles of one substance are identical
3.The spaces between particles are very large compared to the size of the particle - The particles in matter attract one another
- All particles of matter are constantly in motion
What is a physical and Chemical change?
Physical change: usually occurs when heat ( energy ) is either added or taken away. The substance is the same
Chemical change: The substance are changed chemically and display different physical and chemical properties after the change
What is chemical and physical properties?
Chemical: Properties that can be observed or measured when a substance undergoes a chemical reaction
Physical: Properties that can be observed without bringing a chemical change
Who was Democritus?
pounded up materials in his pestle and Mortar until he had reduced them
to smaller and smaller particles
Which he called atoma Cindivisible)
Who was John dalton
I. Matter is made of Small indestructible partees
called atoms.
2. Atoms of the same element
are identical to one another
3. Atoms of different elements nave different properties
4. Atoms can Join together to form
molecules.
Who was Thomson?
Discovered the electron using eathode ray tubes. And developed the plum pudding model
Who is Rutherford
- Conducted the gold fail
- They fired helium nuclei particles at a piece of gold fail which was only a few atoms thick
- Most of them passed through but 1% of them were deflected
- He found there was something in the middle know as the ( central nucleus )
Who was Bohr?
- Conducted test similar to flame tests with cathode ray tube experiment
What is complete and incomplete combustion?
Complete combustion occurs in an unlimited supply of air, oxygen in particular
Incomplete combustion occurs when a combustion reaction occurs without a sufficient supply of oxygen. And if there’s carbon or carbon monoxide.
What is an example of complete and incomplete combustion?
Complete- Burning candle wax
Incomplete- burning paper
Hydrogen- burning splint test
Insert a burning splint into the test tube of gas. If there there is a sharp pop then it’s hydrogen
Oxygen glowing splint test
Light a splint then blow it out so there is a glowing ember on the end. Insert the glowing splint into the gas if it bursts into flames it is oxygen
Carbon dioxide limewater test
Mix the gas with clear, colourless limewater. If the limewater turns cloudy then the gas is carbon dioxide
Water cobalt chloride test
Hold a cold surface near the suspected water vapour to collect some condensation. Touch a piece of cobalt chloride paper to the liquid. If it changes from blue to pink it’s water
Substance
Substance
Pure
Element Compunds
Substance
Mixtures Homogeneous Heterogeneous
Mixtures Mixtures
Element vs compound
Element- a pure substance that cannot be broken down into simpler substance by chemical reaction. Smallest piece of an element is an atom
Compounds- substance made of 2 or more elements that are chemically bonded to each other
Heterogeneous mixtures
- Can see it is two different things
2.can sometimes be separated by filtrations. - Large particles get caught by the filter
What is the periodic law?
When elements are arranged in order of increasing atomic number there is a periodic pattern in their physical and chemical properties.
Metals
Shiny, maleable, Conduct heat, and electricity
Non metals
Dull, brittle, do not conduct heat or electricity
Metalloids
Have some metal and some non metal properties
Are there more element or compounds?
There are more compounds because you can mix and match so there is endless possibilities
Why is hydrogen in the same column as the alkali metals?
Because they all have one outer electron
What is an isotope?
Isotopes are members of a family of an element that all have the same number of protons but different number of neutrons
