Chemistry part one Flashcards
What does WHMIS mean?
Workplace Hazardous Materials Information System.
What are the three states of matter?
Solid
Liquid
Gas
What are properties?
Characteristics used to describe a substance.
What are physical properties?
Properties that explain the appearance and composition of a substance.
Ex: Texture, colour, density, melting point
What is physical change?
Any change not involving a change in the substance’s chemical identity. Changes only in physical properties.
Ex: Change of state (melting, freezing, evaporating)
What are chemical properties?
They explain how a substance reacts with another substance.
Ex: Ph, Reactivity, Toxicity
What is chemical change?
Two or more substances that react and one or more new substance(s) are formed having different properties.
Ex: Combustion, Burning
What is a pure substance?
Consists of only one kind of matter and has its own unique set of properties. Elements and compounds are pure substances. Ex: water, gold
What is an element?
A material that cannot be further broken down. Building blocks for compounds.
What are Compounds?
Two or more elements chemically combined in a specific arrangement and proportion.
What is a mixture?
A physical combination of pure substances. Each substance retains its properties since there is no chemical reaction that takes place. Ex: Kool Aid, Butter and flour
What are the four types of mixtures?
1) Mechanical mixture- each substance that makes up the mixture is distinct or visible.
2) Solution- the substances are not visible or distinct
3) Suspension- tiny particles of one substance is held within another cloudy mixture. The particles can be filtered out.
4) Colloid- Another cloudy suspension but the particles cannot be filtered out.
What is solute and solvent?
Solute- the thing being dissolved
Solvent- the thing the solute is being dissolved in
What is the Tyndall affect?
Light is scattered when put through the substance due to the particles.
What is evidence of chemical change?
1) Change in colour
2) Change in Odour
3) Formation of solid or gas (precipitation)
4) Release or absorbtion of heat (exo or endothermic)
What did John Dalton do?
He suggested that matter is made up of solid spheres called atoms.
What did J.J.Thomson do?
He suggested that electrons are embedded in the atom.
What did Hantaro Nagoka do?
He refined the idea saying electrons orbit the central positive mass.
What did Ernest Rutherford do?
He suggested that the nucleus is made up of protons.
What did Bohr do?
He suggested that electrons exist in specific motions.
What did James Chadwick do?
He refined the idea suggesting the nucleus is made up of positive charged protons and neutral neutrons.
What did Quantum Mechanics do?
They found that electrons exist in a charged cloud around the nucleus.
Who organized the Periodic table of elements? How did he do it?
Dimitri Mendeleev.
He wrote them on cards and arranged them until he found a pattern. This layout followed increasing atomic mass and grouped elements with similar properties.
What are periods?
Horizontal rows, numbered 1-7.
What are groups/families?
Vertical rows, numbered 1-18. Elements in the same group have similar properties.
What is Group One?
Hydrogen and Alkali Metals. Most reactive metals, react with water and air, reactivity increases as you move down the group.
What is Group Two?
Alkaline-Earth Metals. They react with air and water but are less reactive than alkali metals.
What is Group seventeen?
Halogens. They are the most reactive non-metals and tend to combine with other elements to make compounds.
What is Group Eighteen?
Noble gases. The most stable and unreactive elements.
What is Atomic number?
How many protons are in the nucleus of an atom of an element, same as the number of electrons.
What is Mass Number?
The total mass of all protons and neutrons in an atom.
How do you calculate the number of neutrons?
Subtract the Atomic number from the atomic mass.
What are the properties of a metal?
- shiny
- malleable
- ductile
- conducts electricity
What are the properties of a non-metal?
- can be a solid or a gas
- dull and/or brittle (only for solids)
- does not conduct electricity
What is Atomic mass?
Quantity of matter in an atom.
