ChemistrySemester 1 Final Ciera Johnson Period 2
StaTes of Matter Changes There are three basic states of matter, solids, liquids, and gasses. When a physical change happens it For them to be able to change does not change anything states it requires energy in the chemically. Example would be forms of heat and pressure. when water freezes, or boils. When a chemical change happens itThese changes can be either changes the chemical composition.intensive or extensive property. It looks different. Example wouldIntensive properties do not depend be burning paper.on the size and is the color ordensity of the sample while You can remember theextensive properties do depend on difference between them by athe size of the sample because it physical change is reversible,deals with the mass and volume. while chemical is not.
Scientiﬁc NotationThe number in scientiﬁc 5.67 x 10^5 -->567,000notation are made up of 3 Exponentparts: the coefﬁcient, the base Coefﬁcient Baseand the exponent. When the exponent is positive we move the decimalREMEMBER: The to the right, when it is negative we move to the left.coefﬁcient must be So in the one above we move it to the right, while thegreater than or equal to one below we move to the left1, but greater than 10,The base must be 10, 9.02x10^-7 --> 0.000000902exponent shows thenumber of decimal When we do it reversed, the rules apply. When theplaces that the decimal number is positive we move it to the left 10 spaces somoved the exponent is 10. 56,760,000,000 --> 5.676x10^10
Scientiﬁc FiguresDigits from 1-9 are always signiﬁcant. 0.007- there is only oneIf the number does have a decimal all the signiﬁcantzeros to the left will not count as a signiﬁcant digit.digits until there is a signiﬁcant digit.If the number does not have a decimal, the 5057- there arezeros will not count as a signiﬁcant digits four signiﬁcantuntil there is a signiﬁcant digit. digits.Just make sure to count out the zeros correctlyand keep in mind that the zeros that are inbetween the numbers are consideredsigniﬁcant.
Periodic TableElements are organized on the table according to 118 k nowntheir atomic number, usually found near the top ofele mentthe square. s!The columns of elements are called groups orfamilies, each horizontal row of elements is called aperiod.Elements in each family have similar by not identicalpropertiesThe elements in a period are not alike in propertiesThere are three main types of elements: Non-Metals,Metals and Metalloids
Calculating densityDensity = mass/VolumeDensity is the degree of compactness ofa substance(Usually density is expressedin grams/milliliter)basically you divide the mass by thevolume. D=9g/3cm^3 D= 3g/cm^3If you have a small box, and it has amass of 9g and a volume of 3cm^3 ﬁndthe density.