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Science 20

Stack #15061

Science 20 Qs - ChemestryScience 20 As - Chemestry
significant digits rule is ... do not count leading zero's, but do count trailing zero's
do not add zero's unless they are ... significant
put a zero in front of a decimal but _______ count it as significant do not
certainty rule is ... when multiplying or deviding, round the answer to the smallest amount of digits in the question
precision rule is ... when adding or subtracting, round the answer to the smallest number of decimal places
_________the last significant digit in your answer round off
do not round off the number until ... the end of the question
with scientific notation you ... move the decimal place so that only one non - zero digit appears to the left of the decimal
drop all ____________ zero's non - significant
multiply this number by 10 coefficient n, where n is... the number of places the decimal was moved
when the first digit after thoes retained is less than 5 ... all digits retained remain the same
when the first digit after thoes retained is greater than 5 ... the last digit retained is increased by one
there are ____ different elements 109
one atom of a particular element is represented by a ... symbol
the symbol is either a capital letter by itsself or ... a capital letter followed by a lower case letter
the symbol for carbon is ... C
the symbol for cobalt is ... Co
atoms combine together to form ... molecules
a molecules is represented by symbols placed side by side to form ... formulas
different kinds of atoms combined together produce ... a molecule of a compound
in the formula H2O, the number 2 is called a ________ subscript
the subscripts in a formula tell the ______________ in the molecule number of each kind of atom
some molecules are made up of two or more ... atoms of the same element combined together
elements of the same kind form together when ... they don't want to be alone (they are unstable and become more stable when paired)
Dalton's atomic structure ... invisible and round like billiard balls
Thompson's atomic structure ... positive sphere, embedded electrons almost like a raisin bun
Rutherford's atomic structure .... small positive neucleus surrounded by electrons
Bohr's atomic structure .... certain number of electons in quantisized energy levels
protons and neutrons are found in the inner core of the atom called ... the neucleus
______ are found moving around the outside of the nucleus electrons
Created by: Tigger 27