Unit 1-6 basic chem ccm test 1

percent composition

% of element= mass element/mass compound x100%

% mass by element

%mass by element= (# moles of element)(mm)/(1 mole)(mm of compound)

cation

(+) metal loses electron -smaller than parent bc looses electrons

anion

(-)non metal gains electron -larger than parent bc gains electron

temp conversions

(formulas in green packet:)

electronegativity trend

- ability of atom in molecule to attract electrons to itself up, right - increases as size decreases smaller atom attract neighboring electrons

ionization energy trend

- energy req move least tightly bound electron from atom up, right

ionic compounds

- have cation and anion -high melt points using formula unit subscripts are smallest whole num possible

ionic compound naming

- metal or polyatomic ion -if in group 1a, 2a, or Al, Cd,Zn = NO ROMAN NUMERAL -others need roman numeral hydrogen is nonmetal "end in ate and ite"

molecular compounds

- molecular formula -need prefix

group 5a, 6a, 7a gain electron

5a= -3 6a=-2 7a= -1

protons

= atomic number

transition metals form cations except:

Ag, Zn ^2, Cd^2

6 strong acids**

Hcl, Her, Hi, Hno3, H2so4, Hclo4 turn into ions when dissolved -produces hydrogen atoms when dissolved in water

amu

atomic mass unit 1amu=1.66x10^-24g

neutrons

atomic mass- atomic number

isotopes

atomic number is same atomic mass is diff -diff isotopes of element not equally distributed

periodic table: row (left to right)

called period every atom in period has same valence electrons

molecular formula

can be simplified

law of conservation of mass

can't be created or destroyed

empirical formula

can't be simplified to whole numbers

energy

capacity to do work

double displacement reactions

cations and anions are switched ex; ax+by-> ay+bx

water chem prop

decomposed using electricity reacts with sodium and potassium reacts with carbon mon at high temps

prop of matter: extensive properties

depends on amount of substance ex:mass/volume

volume displacement

displaced is volume of solid

atomic radius trend

distance from atom nucleus to valence electrons - down, left

groups( vertical columns)

elements in each group similar chemical and physical prop

kinetic energy

energy of motion ex: in the middle of a dive

pure substance

every sample is same unique set of properties element or compound

decomposition reactions

form simpler compounds ex:ab_> a +b

Polyatomic ions

green sheet, 2+ covalently bonded atoms

*strong bases to know

group 1a and 2a metals nah, lioh, koh, ca(0h)2, ba(oh(x, sr(oh)2

metalloids

have some properties of both ^ -electrical/thermal conduction increases with increasing temp

activity series chart

higher in series, more active than one below and will kick it out of compound

accuracy

how close measurement is to true value

precision

how reproducible multiple measurements of same thing are

polyatomic ions

hydroxide cyanide

metals

left of stair line solid room temp high luster ductile, malleable high melting points, form ions by loosing electrons can't combine with each other

adding/subtracting with sig figs

lesser amount after decimal is the amount should be in answer

chem change

makes new substance ex:rusting of iron

stoichiometric equivalencies

many moles of each element contained in a compound there are in one mole of the compound ex: 9mol carbon in c9h804

isotopic designation

mass number charge element symbol atomic number

Density

mass(g)/volume(mL)

prefixes

mono di tri tetra penta hexa hepta octa nona deca

scientific notation : moving decimal to right

negative exponent

heterogenous mixture

nonuniform composition ex:sand+water, iron+sand

prop of matter: intensive properties

not depend on amount ex:density, bp, mp, color

single displacement reactions

one element displaces the other, depends on reactivity - ex: ax+y _> ay+ x(anion rep) ax+b->bx+a (cation rep)

polyatomic molecules

p4 s8 03

scientific notation: moving decimal to right

postive exponent

mixture

pure substance that was physically combined homogenous heterogenous

combustion reaction

reaction of an element with oxygen -can also be a synthesis

single displacement continued

replacement of halogen by more active halogen replacement of hydrogen in acid by metal replace hydro in water by metal real of metal by more act metal

atom

retains chemical prop of that element

non metals

right of stair line all states of matter, low luster poor electrical, thermal conductivity not ductile, low melting points, form ion by gain electrons, combine with metal, metalloid, non metal

law of constant composition

same proportions of mass elements

element

simplest form of matter made up of 1 unique atom, can't be broken by chemical/physical methods

potential energy

stored energy ex:standing before dive

chemistry

study of properties of matter/changes it undergoes - changes through atoms bonding

physical change

substance changes physical appearance wo altering identity ex: freeze, dissolving

Dimensional analysis

sucks, practice it!

electrons

take atomic number, figure out charge( + subtract from atomic number, if - add to atomic number= electrons)

homogenous mixture

uniform every sample is same ex:air, salt water, bronze

multiply/divide with sig fig

amount with least amount sig fig for answer

7 Diatomic elements

02 n2 f2 cl2 br2 I2 H2

3 rules to displacement

1- solid must be more dense than water 2- solid can't dissolve in liquid 3- solid can't react with liquid

zero rules for sig fig

1- zeros btw always signif ex: 203= 3 sig fig 2- zeros w/o non zero in front not sig ex:0.1=1 sig fig 3- zeros end number with decimal are sig ex: 125.00= 5 sig fig 4- assume 0s end number w/o decimal not sig ex: 1200= 2 sig fig

5 methods of separating mixtures

1-evaporation 2-distillation 3-chromotography 4-filtering 5-centerfigation

density of water

1.0 boiling pt-100 degrees celsius freezing-0 degrees celsius

1a- 2a- 7a- 8a-

1a- alkali metals 2a-alkaline metals 7a-halogens 8a-noble gases

group 1a, 2a and 3a loose electron so

1a= +1 2a= +2 3a= +3

1 megaton

1x 10^6 tons

1 deci

1x10^-1m

1 centi

1x10^-2m

mili

1x10^-3m

micro

1x10^-6m

nano

1x10^-9 m

1 kilo

1x10^3 g

molecular compound naming

2 nometals or nonmetals/metalloid -need prefix -end in "ide"

synthesis reaction

2 or more substances combine to form a new one na+cl->nacl

compounds

2+ elements, whole number ratios held by chemical bonds ex:nacl -can be separated by chemical methods