Observation

using all five senses to watch something carefully for a period of time. (Scitific Method)

e.g. The tablet was dissolving in the water quickly; we could see a lot of bubbles.

Question

Asking for unusul situations or information.

e.g. Does temperature affect the rate of reaction?

Hypothesis

An idea is suggested as a possible way of proving an idea, which has not yet been show ture.

e.g. Temperature does affect the rate of reaction.

Prediction

Something that you say is going to happen; an important step before any experiment.

e.g. If the tablet dissolves faster, then the temperature affect the rate of reaction.

Experiment

Test using scientific methods to discover how things reacts under certain conditions.

e.g. Put tablet into the hot water, dissolved.

Procedure

The correct way of doing something; the plans and steps for a experment.

e.g.         1.Cut the tablet into four piece

               2.Put the tablet into the water

               3.Record the time of fully dissolving

Data Collection

Information, numbers, or facts that show in a experiment being collected. There are many ways to collect data. We can use graph, table, and diagram.

e.g.

Temp.           20^。  water      40^。 water

Time（s）    68s                30s

Analysis

A careful examination of something in order to understand and reasoning.

e.g. The tablet dissolves faster in hot water; it means heat make the rate of reaction faster.

Conclusion

Something that you find out after considering all the facts and information you have.

e.g. Temperature does affect the rate of recation. The molecule moves faster when gets hot

Three kinds of variables & Controlled experiment

Manipulated variable(independent variable): something that intentionally changed by people.

Responding variable(dependent) :the things that affected as a result of the change of manipulated variable.

Controlled variable: something that not change, keep constant in order to be efficient.

Controlled experiment: Using the idea "control" to make sth. constant during the whole experiment.

Proton

A stable subatomic particle carry positive electric charge.

The same element have the same number of protons.   [image]

Neutron

A part of an atom that has no electrical charge.

♠ one of the things in every atomic except ordinary hydrogen.

[image]

Nucleus(nuclear)

The central part of an atom, which is densely packed with protons and neutrons.

It makes up almost all of the mass of an atom.

[image]

Electron

Lightest electrically charged piece that moves around the nucleus of an atom in high speed.

* electrons closer to the nucleus are more tightly[image]

Subatomic Particles

(Elementary Particles)

Any units of matter and energy.

There are more than 200 subatomic.

e.g. Ca, O, Zn, Cl...are all elements.

Atomic Number

It is the number of protons. It organizes the "things" elements.

*In a neutral atom, the atomic number also equate with the number of electrons.

e.g. There are 12 protons in Mg's atom, so we can say the atomic number of Mg is 12.

Nuclear Charge

The electric charge of a nucleus. Since nucleus is densely packed with protons and neutron, and neutron has no charge, the charge of the protons is actually the charge of the nucleus.

e.g. Hydrogen has only one protons, so we can say its nuclear charge is positive 1.

Nuetral

A neutral substance is neither acid nor base.

It can also mean the same number of protons and the same number of electrons make the atom "seems like" on charge.

Atomic Charge

The Charge of atom.

Neutron has no charge, and proton has positive one charge, and electron has negative one charge.

* Normally, there are same number of protons and electrons in a neutral atom, so protons are balanced by electrons.

Atomic Mass

The mass of protons is approximately equal to neutrons, and the mass of electrons is very light, so atomic mass is mostly protons and neutrons.

Mass are relative; it's not the actually mass but it's a ratio compare to the 1/12 of Carbon mass.

Atom, molecule, element, and compound

Atom   the smallest part of an element(can form molecule）

Molecule the unit that can be divided, usually consisting of two or more atom.

Element  It constitude all matter in the world. Atom is the smallest units of elements.

Compound  It contains atoms from two or more elements

Comparing atom and ion

Atom  the smallest unit of an element. Normally, an atom means it's neutral; protons' and electrons' number stay the same, so atom seems like no charge.

Ion  an atom which has been given or kaken away electrons. It has to have one or more + or - electric charge.

Ionic  Charge

[image]

It's the charge of an ion; it has to have a neither postive charge or negative charge.

Cations and Anions

Cations are positive ion; they are metals who lose electrons.

Anions are negative ion; they are non-meatals who gain electrons.

e.g. Mg ion is a cation; Cl ion is a anion.

The Periodic Table

[image]

It organizes all the chemical elements in approximately increasing order of their atomic mass.

Period(row)

It's the rows that go across the periodic table.→

• From left to right, element increase by 1 proton
• same number shells going across
  

Familes(column)

It's the vertical groups that going down in the periodic table .

• The element that in the same family behave in similar ways

• they have same number of electrons on outer shell
• while going down, each element increase by 1 shell(ring)
• There are four big familes
  

Meatals and non-metals

They are separated by a →          line.

   ↓

         →

               ↓

Metals lose electrons to form positive ion, non- metals gain electrons to form negative ion.

Alkali Metals

The metals that forms a chemical salt when combined with an acid.

The Alkali metals are in the first group.

Alkaline Earth Metals

Metals that contains alkali. They all have postive two ion charge.

They are in the second group.

Transition Metals

They are the metals from group 3 to group 12.

Noble Gas

They are the non- metals in group 18. They are very unreactive since they all have a full valence shell which are considered stable.

Halogen

They are in group 17. Five of them are hightly reactive with most metals.

Bohr Model

[image]

It shows all the shells and electrons outside the nucleus.

• As we going right of the periodic table, it increses one electron outside .
• The same groups have the same numbers of electrons outside
• The elements in the same period increase one shell as we going right
  

Lewis Diagram

The diagram that only shows the most outer shells of the elements.In the same group, the number of electrons stay the same.

• Since they have the same numbers of valence electrons, they are behave similar.[image]
  

Valence Electron

The numbers of electrons in the most outer shell, and they dicided the proporties of different elements.

Valence Shell

The most outer, final shell.

Comparing Bohr Model and Lewis Diagram

The Bohr Model shows all the rings and all the electrons outside the nucleus.

Lewis Model showa only the most outer shell and valence electrons.

Ionic Bond

Metals and non-metals bonding. They both eager to have a full outer shell. So, they come to an arrangement.

 [image]

The metal is attracted to the non-metal and they form a bond.

Ionic Compound

It's simply Metal and non-Metal bond together to form a ionic compound.[image]

Binary Ionic Compound

There is only two elements bond together in a Binary Ionic Compound.(Metal and non-Metal)

Paper Model

It's a easy way to represent the ionic compound. Square is for receiver; circle is for giver.

Chemical Formula

Using abbreviation to write the word of the elements, showing how many elements are in the compound and the number of atom in each element.

e.g.  Al₂ O₃    Co₂ (SO₄ )₃

Combining Capcity(CC)

It's simply the ion charge(s) that shows in the periodic table.[image]

Subscripts

The small number on right side of the elements. It indicates the number of each atom in the compound.

e.g.  Ca₃    Fe₄

Multivalent

It means the elements have more than one ion charge.

[image]

Polyatomic

There are more atoms in the ion.

[image]

Covalent Compound

It's non-Metal and non-metal bond together form a compound. (connection)

e.g. O₂  CO₂

Covalent Bonding

It's non-metal share electrons with other non-metal. Atoms overlap tightly, and the unpair electrons from each atom will pair together.

e.g. NH₃

Unpair Electron

They are the singular electron found in the valence shell.(Before boning)

Bond Pair Electron

They are the paired electrons found in a covalent bond.

Lone Pair Electron

They are already paired, no bonded, found in the valence shell.

Diatomic Molecules

It's a pair of atoms of the same element that are joined by covalent bonds.

e.g. H₂ O₂ At₂

Prefix

When we are writing the formula for covalent compound, we use prefixes to determine the number of atoms present for each element.(if the first one has only one atom, we don't need then)

e.g. Carbon disulphide

Materials For Lab

Test tube: glass that can be heated and can be used as the place where the reaction happens.

Wooded splint:use to be burn in the flame

Bunsen burner:provides heat and flame

Glass stirring rod: used to mix things.

Goggles: never forget when doing a lab!!

Chemical Reaction

It's the process of breaking or rearrange chemical bonds through chemical change.

Oxygen gas+Hydrogen gas→water

Reactant

It's the things that we start with a chemical reaction.

e.g. H_{2 +} O₂  →H₂O(product)

Product

It's a new chemical compound produced by chemical reaction. We call it “finished thing.”

e.g. H_{2 +} O₂  →H₂O(product)

Precipitate

It's some substances that forms by a chemical reaction.

e.g. Iron(111)hydroxide is the precipitate that form after Iron(111)chloride add to sodium hydroxide.

Chemical Equation

The equation that shows the reactant, product...all the basic information of a chemical reaction.

e.g   2Be+O₂ → 2BeO

Skeleton Equation

It's the unbalanced equation.

e.g.  H₂+O₂ →H₂O

Balanced Equation

The equation that shows the Conservation of Mass. The number of atoms of each element are stay the same before and after reaction.

e.g.    2P+5O₂ →2PO₅

Physical Change

There is no new bond created, like size change, states change density change...

e.g. Melting ice becomes water, and boiling water becomes steam

Chemical Change

There are new things being created after a chemical changed.

e.g. The candles creates water and CO₂

Law Of Conservation Of Mass

Once balanced mass before equals mass after. The number of atoms stay the same for the whole time.

 e.g. 3Fe+2O₂→3FeO₄

Endothermic Reaction

Heat energy is absorbed with reactant.

NH₄SCN+Ba(OH)₂+energy→H₂O+NH₃+Ba(SCN)₂

Exothermic reactions

Energy is give out while a chemical reaction.(become hotter after reaction)

H₂O₂+Kl→Kl+H₂O+O₂+energy

Energy

It can be heat. It's something that absorded with the reactants or give out by the reactant.

Rate of Reaction

The speed of a chemical reaction.

Temperature, concerntation, surface area, and catalyst are the factors affect the rate of reaction.

High temp. make it faster, more amount of reactant make ir faster, bigger surface area makes it faster, and catalyst can make it either faster or slower.

Synthesis

A+B→AB

two or more things combining into only one thing through chemical reaction.

e.g.          2H₂+O_2→2H₂O

Decomposition

AB→A+B

One compound divided into two or more things through chemical reaction.

e.g.    2 H₂O→2H₂+O₂

Single Replacement

A+BC→AC+B

a single uncombined positive element replaces another positive in a compound. ONlY CHANGE ONE THING

e.g.  3Li+AlCl_3→ Al +3LiCl

Double Replacement

AB+CD→AD+CB

The postive replaces another positive; the negative replaces aother negative.CHANGE TWO TIMES

e.g.  NaOH+HCl→NaCl+H₂O

Combustion

Chemical reaction that using oxygen to produce light and heat.

e.g.   Candle+Oxygen Gas →water + Carbon dioxride

Neutrazation

Bases+Acids→water + salt

e.g. HCl+NaOH→H₂O+NaCl

Catalyst

Necessary for the reaction to happen, happen slower, or happen quicker bur it doesn't react.

e.g.  2KClO₃+MnO₂ (catalyst)   _→2KCl+3O₂

Coefficient

The number put in front of the compound in order to balance the equation.

e.g. 3Fe+2O_{2 →} 3FeO₄

Acids

Substances that have a PH that is smaller than 7.

All acids contains at least one H atom.

Compound contains O may have H on the right side of the chemical formula.

e.g.HCl(aq) HF(aq)

Bases

Substances that have a PH that is larger than 7. All bases must have hdroxide.

(Water is in 7 ‘neutral’)

*Strong base are highly reactive call caustic(danger)

e.g. NaOH

Indicator

We use indicator to find out the level of acidity or basicity .

e.g. Methyl orange, Methyl yellow

PH Scale

It's a numberical scale 1-14, and it shows where acids stand and where bases stand. 1is strong acid 14 is strog base. The more things closer to 7, the more "gental" it is.

(aq)

It equals to compound dissolved in water.(inbetween soild and liqud)

We have to write (aq) after a acid.

e.g. HF(aq)

Isotope?(unknown word)

A element has nuclei with the same number of protons but different numbers of neutrons.

Tin has ten isotopes.

Caustic

It Can burn though things chemically.=

=strong bases

Organic Compound

It's simply the compound that contain carbon element. They are produce by organ.

Exception: CaCo₃  CO₂

e.g. CH₄  CH₃Cl  C₂H₂

Synthetic

Produded by difference fake things, rather than being naturally produced.(opposite: Natural)

e.g.  Nylon

Salt

Actually it is Sodium Chloride.

Produce by the combining of acid and base

Hydrocarbon

A kind of ORGANIC compound.(H+C)

E.g. Methane, Ethane(manufacturing), Propane (Camp fuel).

Alcohols

A kind of ORANGIC compound.(C+H+O)

e.g. Methanol, Ethanol.