Matter is anything that has mass and occupies space. Mass : is the amount of material. Mass : is what gives an object the properties of weight and inertia. Weight : is a force and is due to the pull of gravity on the object. Inertia : resistance of an object to change its motion.
Mass : is the amount of material.
Mass: is what gives an object the properties of weight and inertia.
Weight : is a force and is due to the pull of gravity on the object.
Inertia: resistance of an object to change its motion.
Matter that has uniform an unchanging composition is called a substance, also known as pure substance.
Pure substances are made of only one type of matter.
There are two types of pure substances: Elements and compounds.
Physical properties: Can be observed or measured
without changing the
The ability of a substance to
combine with or change into
one or more other substances.
To observe a chemical property
the composition of the matter
observed must be changed.
Physical properties: density, color, odor, taste, shape, melting point, boiling point, etc.
Chemical properties: the ability of a substance to form rust, the ability of an element to combine chemically with other element, etc.
Copper is reddish
with a bright metallic luster.
It is malleable, ductile
a good conductor of heat and electricity
Density = 8.92 g/ml
Melting point : 1085oC
Boiling point: 2570oC
No definite: occupy all the available space.
No definite: take
the shape of the
No definite: take the
shape of the container
and occupy all the
Less closely packed
than solids and not
rigidly held in place
Very far appart
from each other
A little when
Tend to expand
Expand a lot
Move past each
Solids can´t flow
Physical Change:A change in the form of a substance, but not in its chemical composition; chemical bonds are not broken (or formed) in a physical change.
Examples: bend, grind, crumple, split, crush, melt, dissolve, cut, condense, evaporate, sublimate, freeze etc.
Chemical Change:The change of substances into other substances through a reorganization of atoms.
A chemical changeis a process
that involves one or more substances changing into new substances.
A chemical change is referred as a chemical reaction.
Water is broken into hydrogen and oxygen.
Iron reacts with oxygen to form rust..
Sodium explodes when it reacts with water.
Antoine Lavoisier (1743-1794), the father of modern chemistry, was the first to use the analytical balance to monitor chemical reactions. He explained the nature of combustion.
He also studied the thermal decomposition of mercury (II) oxide.
Problem: In an experiment, 10.00g of red mercury (II) oxide powder is placed in an open flask and heated until it is converted in to liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26 g. What is the mass of oxygen formed in the reaction?
Mercury (II) oxide Mercury + oxygen
10.00 g 9.26 g ?
Prob. 6 and 7 p. 65
8 and 9 (HW)
Pure substances increase gradually their temperature until the melting point is reached. The energy is used to increase the kenetic energy of the molecules.
Then the temperature remains constant during the whole melting process. The energy is used to overcome the forces that keep the particles together.Description of the heating curve of a pure subsatance
Only when all the solid has changed to liquid the temperature starts increasing gradually again(The energy is used to increase the kinetic energy of the particles) until the boiling point is reached.
Then the temperature remains constant during the whole boiling process (The energy is used to overcome the forces to separate the particles even more).
Only when all the liquid has changed to gas the temperature starts increasing again (Once more, the energy is used to increase the kenetic energy of the particles) .
Mixtures, on the other hand, keep increasing the temperature even during the boiling process.
The boiling and melting points of a mixture change respect to the pure substance.
For example a water solution will have higher boiling point and lower melting point than pure water.
matter that can be separeted physically into components parts.
They are made of two or more types
Methods to separate the components of a mixture:
precipitation,decantation, filtration and distillation.
Homogeneous mixtures: is a mixture in which the components are evenly distributed among each other. You can’t see the component parts.
Homo means the same throughout.
It has a constant composition throughout.
Homogenous mixtures are also called SOLUTIONS
Examples:Salt dissolved in water, sugar dissolved in water, apple juice, tea, copper (II) sulfate solution in water, alloys....
States of matter in solution (remember that a solution is an homogeneous mixture)
gas in gas
air ( N2, O2 , Ar, CO2 , other gases)
gas in liquid
soda pop (CO2 in water)
liquid in liquid
gasoline (a mixture of hydrocarbon compounds)
solid in liquid
Filtrated sea water ( NaCl and other salts in water)
gas in solid
H2 in platinum or palladium
liquid in solid
dental amalgams (mercury in silver)
solid in solid
alloys ( brass, (Cu/Zn), sol-der (Sn/Pb), Steel (Fe/C))
Heterogeneous mixture :the components are not evenly distributed among each other. An heterogeneous mixture has two or more distinct phases that are usually detectable. This type of mixture does NOT have uniform properties.
Hetero means: Regions have different properties
Heterogeneous mixtures that look like solutions can be distinguished because they scatter light (Tyndall effect).
Examples: Sand water, oil and water, milk, sulfur and iron, granite, blood...
Water Solutions are transparent. You can see through them.
The mixture remains stable and does not separate after standing for any period of time.
The particles are so small they cannot be separated by normal filtration.
A solution may have a "color" but it will still be transparent.
Law of conservation of energy: There is no loss or gain of energy. Energy changes from one form to another.
During nuclear reactions matter can change into energy and viceversa: E=mc2
Pure substances are made of only one type of matter. There are two types of pure substances: elements and compounds.
Compounds : pure substances made of more than one type of atom. Compounds can be broken into two or more elements by chemical means.