Unit 2, Chemistry Flashcards
What are the four clues of chemical change?
- Coulor
- Gas is produced
- Heat is produced
4.Liquis is produced
Elements with similar properties are grouped together into families/coloums called groups.
Locate in the periodic table, # of valence electrons, type of compounds usually formed.
Alkali Metals, Alkaline Earth Metals, Halogens, Noble Gases.
Alkali metals are the first column (-hydrogen), 1 valence electron, ionic.
Alkaline earth metals are second column, 2 valence electrons, ionic.
Halogens are the 17th coloumn, 7 valence electrons, covalent/molecular and ionic.
Noble gases are the 18th(final) coloumn, 8 (full) valence electrons, covalent/molecular and ionic.
Where are nonmetals and metals located periodically
metals are on the left side while nonmetals are on the right, divided by the zig zag line.
Cation definiton + examples
a positivly charged ion formed by less electrons. Ex, Calcium: Ca.2+, Silver: Ag.+, Aluminum: Al.3+
Anions definition + examples
a negativly charged ion formed by more electrons. Ex, Chlorine: Cl. –,
Hydroxide: OH. –, Iodide: I. –
How to find protons
The number of protons is equal to the atomic number of the element.
how to find electrons
If it is a neutral atom, the number of electrons is equal to the proton number(AKA # of the element).
If postivly charged, subtract the charge from # of element.
If negatively charged, add the charge to the # of element.
what is H__________?
H O F Br I N Cl
What are the two types of acids? Whats the difference? How to write names?
Binary and Oxyacids
Binary acids contain hydrogen and another element. Named using prefix -HYDRO-stem of the element name-ends in-ic
Oxyacids contain two or more elements. Commonly H#O. Named the same as binary but without hydro. Closly realted to polyatomics, H+polyatiomic then criss-cross.
Whats an ionic compound
created between a metal and a non-metal, the metal GIVES its valence election(s) to the non-metal
Naming ionic compounds
metal name first then the non-metal name after, change the ending of the non-metal name to -ide.
ex, sodium chlorine –> sodium chloride
Formulas for ionic compounds
symbol of metal first, then symbol of non-metal right beside it, criss-cross the charges of the atoms then write them as subscripts
Naming ionic compounds w/ multivalent metals
same thing as normal namings but must indicate which version of metal in the name by roman numeral
Formulas for ionic compounds w/ multivalent metals
same thing as normal (criss-cross method) but aware of the roman numeral in the name
What is a polyatomic ion
A group of atoms with an overall charge
*-ite is always one less oxygen than -ate
Naming ionic compounds w/ polyatomic ions
same thing as normal naming, the polyatomic acts as the non-metal,
but DO NOT CHANGE THE ENDING OF THE POLYATOMIC
Formulas for ionic compounds w/ polyatomic ions
same thing as normal (criss-cross method)
put brackets around the polyatomic when necessary
What are Molecular/Covalent compounds
compounds that contain 2 non-metals
bond with a SHARED valence electron
Naming molecular/covalent bonds
to name look at the subscripts and use prefixes
if the first non-metal is only one do not write mono- only when its the first
(NO CRISS-CROSS)
Formulas for molecular/covalent bonds
look at the name and determine subscripts based on prefixes
All the prefixes
one - mono
two - di
three - tri
four - tetra
five - penta
six - hexa
seven - hepta
eight - octa
nine - nona
ten - deca
Law of Conservation of Mass
the total mass of the reactants always is the same as the mass of the products
only 100% accurate when the reaction occurs in a completely contained environment, ex if gas is lost then the reactants =/= products
Balancing equations
use coefficients to balance atoms on both sides of the equation
Synthesis
two or more elements or compounds combine to form a new product which is a compound
general formula : A + B = AB
(when writing the product write it as the formula that the reactants would have made.
ex, crisscross method when metal +non-metal)
