CHEMISTY Q1

VOCAB

Chemistry: is the study of matter and the changes it undergoes.

Ex: cooking on a metal pan, different shampoos for your hair and fibers in your clothing.

Mass: is the measurement of that reflects the amount of matter.

Weight: is the measurement of earths gravitational pull-on matter.

Matter: is anything that has mass and volume and takes up space.
Ex: books, stars, tables, people.
Not matter space, light, thoughts, radio waves.

Applied research is research you do to solve a specific problem.

Ex: how to bake a cake? How to study well?

Pure research: is research you do to gain knowledge.

Ex: is there life on mars? Do stars actually glow?

Chemist: is likely to be working in more than one area of chemistry at a given time.

Applied chemistry is directly toward a practical or application.

Ex: medicine, or environmental science.

Branches of chemistry:

Organic chemistry: is defined as the study of all chemicals containing carbon (most carbon
containing chemicals plastics, soaps, and perfume).

Inorganic chemistry: is the study of chemicals that don’t contain carbon. (Mostly non-living
things, like rocks and minerals and water).

Biochemistry: the process of living organisms.

Ex: metabolism or fermentation or food digestion.

Physical chemistry: the behavior and changes of matter and related energy changes
Ex: reaction rates.

Analytical chemistry: is the study of components and compositions of substances.

Ex : food nutriments, quality control.

Second Lesson :
VOCAB

Substance or pure substance is matter with a uniform or unchanging composition.

Ex: gold, silver, table salt, and pure water.

States of matter: matter that exists naturally on earth and can be classified as physical forms.

 Solid: is a form of matter that has its own definite (unchanging) shape and volume.
o Ex: wood, iron, paper, sugar.
 Important: the particle of a solid are tightly packed when heated it expands but only
slightly because its shape is definite.

 A solid might not confirm the shape of its container.

Ex: you take a rock and put it in a container it won’t take its shape.

 A solid also can’t be compressed into smaller volumes so its incompressible.

 Liquid: is a form of matter that flows and has constant volume and takes the shape of its
container.
o Ex: water, blood, mercury.
 Important: its particles are rigidly held in place and are less tightly packed than the
solids.

 Liquid particles are able to move past each other, this makes the liquid flow and take shape
of its container.
 Liquids have a doesn’t have a definite shape but has a definite volume. This means that
liquid will take the shape of a container, but it can’t be compressed.

 Gas: is a form of matter that not only flows to fill the shape of a container but also fills
the entire volume of its container.
o Ex: oxygen.
 Important the gases particles are far apart. Because they have space in between them
they are easily compressed.

 Vapor: is the gaseous state of a substance that is liquid or solid at room temperature.
 Ex: steam is a vapor of water in room temperature. Or fog because its water in a gaseous
form. Like boiling water, the steam is a vapor.

 Plasma: is a form of matter when particles of gas become ionized and are broken into
smaller charged particles.
 Important: ionization required energy such as electricity, a fluorescent bulb or electric
current in neon.
o Ex: lighting, aurora, plasma ball, or a neon light.
Extensive properties: depends on the amount of substance present. (Change when u change
amount of matter)
Ex: mass, length, weight, volume, size.
The amount of weight of 2 apples are not the same to the amount of weight of 10.

Intensive properties: don’t depend on the amount of substance present. (don’t change when
you change amount of matter).
Ex: density, boiling point, melting point, color.
The color of 2 apples in a box are still the same of the box with 5 apples.

THESE PROPERTIES ARE PHYSICAL PROPERTIES

Physical properties: is a characteric of matter that can be observed or measured but doesn’t
change the samples composition.
Ex: density, color, melting point, or boiling point.

Chemical properties: the ability or inability of a substance to combine with or change another
substance to create a new substance.
Ex: cooking an egg, buring wood, rusting, rotting banana, fireworks.

Physical change: is a matter that changes its form but not chemical identity:
Ex: melting, boiling, cutting a cake or shredding paper.

Chemical change: is when a chemical reaction from a new product.

Ex: rotting, rusting, digestion, combustion.

LESSON 3:

Physical change: is a change that alters a substance without changing its composition.
Ex: melting an ice cube, cutting a cake, breaking glass, or chopping wood.

Phase change: is a transition of matter from one state to another

Ex: melting, boiling, freezing, sublimation, deposition.

Chemical change: is a process that includes one or more substances that changes into a new
substance.
Ex: boring wood, cooking an egg, rusting, rotting, digestion.

 A chemical change is often referred to as a chemical reaction

 A chemical reaction always produces a change in properties.
  In chemical reactions the starting substances are called reactants and the new
substances that are formed are called products.
 An example of chemical reaction is spoiled food, rusting, tarnish, burnt food.

Law of conservation of mass: states that mass is neither created nor destroyed it is conserved.

LESSON 4:

All matter can be broken down into small basic building block called elements.

Elements: are a pure substance that cannot be separated or broken down into simpler
substances by physical or chemical means.
Ex: helium, gold, hydrogen.
 On earth there are more than 90 elements that occur naturally.

 There are also several elements that have been developed by scientists.

 Each element has a unique chemical name and symbol.

The chemical symbol consist of one two or three letters the first letter is always capital, and the
remaining letters are always lowercase.

Dimitri Mendeleev: in 1869 chemist Mendeleev created a chart which organized all of the
elements that were known at that time.
His classification was based on the similarities of masses of the elements
His table was the first version of what has been further developed into the periodic table of
elements.

Periodic table: organized the elements into a grid of horizontal rows called periods and vertical
rows called groups of families.

 Elements in the same groups have similar chemical and physical properties.

Compounds: is made up of two or more different elements that are combined chemically in a
fixed ratio.
Ex: table sat (NaCl) water (H2O)

 Most matter in the universe exist as compounds.

 Compounds can be broken down into simpler substances by chemical means

 But separating them into elements requires external energy like heat or electricity.
Electrolysis: it is used to chemically change water into its component’s elements – hydrogen
and oxygen.

Law of definite proportions: states that a compound is always composed of the same elements
in the same proportion by mass no matter how large or small the sample is.

 The relative amounts of the element in a compound can be expressed as percent by mass.

 Percent by mass is the ratio of the mass of each element to the total mass of the compound
as a percentage.

 Mass of element / mass of compound X 100.

Law of multiple proportions: states that when different compounds are formed by a
combination of the same elements, different masses of one element combine with the same
fixed mass of the other element in a ratio of small whole numbers.

LESSON 5:

Mixture: is a combination of two or more pure substances in which each substance retains
individual chemical properties.

Heterogenous: does not have a uniform composition.

Ex: dirt, blood, milk
Homogenous: has a uniform or constant composition. Always has a single phase. It can also be
refred to as solutions.
Ex: lemonade, gasoline, steel.

The process used to separate a mixture are physical processes based on differences in the
physical properties of the substance.

Examples of separations:

Filtration: is a technique that uses a porous barrier to separate a solid from a liquid in a
heterogeneous mixture.

Distillation: is a physical separation technique for homogenous mixtures based on differences

in the boiling points.

Sublimation: is a process which a solid change into vapor without melting. It can separate two
solids in a mixture when one sublimates but the other does not.

Chromatography: separates the components of a mixture dissolved in either a gas or a liquid,

based on the ability of each component to travel across the surface of a fixed substrate.
Crystallization: is a separation technique that forms pure solid particles of a substance from a
solution containing the dissolved substance.

LESSON 6:

The roots of the atomic theory:

Science as we know what today did not exist thousands of years old.

Many philosophers speculated that matter was composed of things like earth, water, air, and
fire.

It was also believed that matter could be endlessly divided into smaller and smaller pieces.

Democritus:

He was a Greek philosopher, in 460-370 B.C. He was the first propose that matter was not
infinitely divisible.

Believed that matter was made up of particles called atoms that could not be created or
destroyed or divided.

What he also believed:

Matter is composed of atoms which move through empty space.
Atoms are solid, homogenous, indestructible, and indivisible.
Different kinds of atoms have different sizes of shapes.

Aristotle:

He was a Greek philosopher in 384 – 322 B.C. He disagreed with Democritus

Aristotle didn’t believe that empty space could exist.

He believed that matter is made of earth, fire, and water.
His ideas went unchanged for 2000 years.

John Dalton:

He was a English school teacher in 1766 – 1844 who marks the beginning of the development of
modern atom theory.

He rived, and revised Democritus ideas based on scientific research.

His research is known as Daltons atomic theory.
Daltons atomic theory:
Matter is made of extremely small particles called atoms.
Atoms are indivisible and indestructible
Atoms of a given element are identical in mass and chemical properties.
Atoms of a specific element are different from those of another element.
Different atoms combine in simple whole number rations to form compounds.
In a chemical reaction, atoms are separated, combined, or rearranged.

LESSON 7:

MORE INFO IN POWERPOINT REVISE THERE BETTER!!!

Atom: the smallest particles of and element that retains the properties of the element.
STM: allows individual atoms to be seen.

Cathode ray: are a stream of particles carrying a negative charge. These particles caring a
negative charge are electrons. (what jj Thomson used to discover the electrons).

Nucleus: is the extremely small positively charged, dense center of an atom that contains
positively charged protons and neutral neutrons.