chemistry Flashcards
define WHMIS
Workplace hazardous materials information system
define properties and physical properties
Properties - characteristics used to describe a substance
what is a physical change
Physical Change – Any change not involving a change in the substance’s chemical identity. A physical change involves only a change in physical properties. In other words, the type of matter has not been changed.
give examples of physical changes
Changes of state
Dissolving
Absorption of water into a towel
Crumpling a piece of paper
Pulling copper into a thin wire (change of shape, but not change of composition)
Cutting a material
Breaking glass
Writing on a Sheet of Paper
what is chemical change give examples
Chemical Change – when two or more substances react and one or more new substances are formed having different properties from the initial substances.
Examples include:
Combustion
Mixing an acid and a base
Photosynthesis
Iron Rusting
what are elements
Elements: a material that cannot be further broken down. These are the basic building blocks for compounds.
what are pure substances
A pure substance consists of only one kind of matter and has its own unique set of properties. Elements and compounds are pure substances.
what is a mixture and what are the types of mixtures
A mixture is a physical combination of pure substances. Each substance retains its properties since there is no chemical reaction that takes place.
Mechanical mixture – each substance that makes up the mixture is distinct or visible. An example is chili.
Solution – the substances are NOT visibly distinct from each other. One substance, the solute, is dissolved into the other, the solvent. An example is Kool-Aid. Substances dissolved into water are called aqueous solutions.
Suspension – tiny particles of one substance are held within another in a cloudy mixture. These particles can be filtered out. An example is tomato juice.
4.Colloid - another cloudy suspension, but with particles so tiny that they cannot be filtered out. An example is milk.
what is evidence of chemical change
change in color
change in odor
forming of solid (percipatate)
forming of gas (bubbling)
Release or absorption of heat or light energy ( warm or cold)
what is group 1 on the periodic table
Group 1 – is divided into hydrogen and the alkali metals. These are the most reactive metals and they react violently in air or water. Reactivity increases as you move down the group
what is group 2 on the periodic table
Group 2 – are the alkaline-earth metals. These metals also react with air and water, but are less reactive than alkali metals.
what is group 17
Group 17 – are the halogens and are the most reactive of the non-metals. They tend to combine with other elements to make compounds.
what is group 18
Group 18 – are the noble gases and are the most stable and unreactive of the elements.
what does the Atomic Number do
of protons in the nucleus of an atom (ie. oxygen always has 8 protons in its nucleus).
Also indicates the # of electrons in the atom, since all atoms are neutral in charge.
what is the mass number what does it do
protons + # neutrons in an atom
mass number can be used to discover how many neutrons are in an atom:
mass # – atomic # = # of neutrons
what is cellular respiration
Cellular respiration takes place in body cells. It is the reaction of oxygen with glucose from food to produce water, carbon dioxide and energy.
C6H12O6(s) + O2(g) 🡪 CO2(g) + H2O(l )+ 36 ATP (energy)
(glucose)
what is corrosion
Corrosion occurs when oxygen in the air reacts with a metal, such as the rusting of iron.
what is combustion
A combustion reaction occurs when oxygen reacts with a chemical to produce a new substance and a release of energy. (burning)
define caustic
able to burn or corrode organic tissue by chemical action