Significant Figures
Leading zeros are __________
What is never significant?
K-39 (93.3%) and K-41 (6.7%) are two naturally occurring isotopes of Potassium. Which mass number would the average atomic mass be closest to?
What is 39 amu?
Formula for hydroxide ion
What is OH-?
Which scientist discovered the electron and came up with a model of the atom known as the “plum pudding model”. He used the Cathode Ray to discover the electron.
Who is J.J. Thomson?
1 L = _____ mL
1000 mL
102.003 (# significant figures)
What is 6?
Why can we not use a "normal average" when calculating the average atomic mass of an element?
What is because it does not take into account the abundance of each isotope.
The formula for nitrate
What is NO3- ?
How many neutrons does Sulfur-36 contain?
What is 20 neutrons?
33.25 cm³= _______ L
What is 0.03325 L?
Easiest way to write a value to show significance of trailing zeros.
What is in scientific notation?
Calculate the average atomic mass of sulfur if 95.00% of all sulfur atoms have a mass of 32 amu, 0.76% have a mass of 33 amu, and 4.22% have a mass of 34 amu.
What is 32.08 amu?
The formula for strontium perchlorate
What is Sr(ClO4)2
An isotope of an element is found to have 6 protons and 8 neutrons.
What is C-14?
Iron has a density of 7.86 g/cm³. Could a block of metal with a mass of 15.3 g and a volume of 4.26 cm³ be iron?
3.59 g/cm³
No, this is not iron
1200 (#significant figures)
What is 2?
The element copper has naturally occurring isotopes of 63-Cu and 65-Cu. The relative abundance and atomic masses are 69.2% for a mass of 63 amu and 30.8% for a mass of 65 amu. Calculate the average atomic mass of copper.
What is 63.62 amu
NH4NO3
What is ammonium nitrate?
Empty space (as it relates to atomic structure)
What is the majority of the volume in an atom?
A newborn baby weighs 2900 grams. The weight of this baby in pounds is ______? 1 kg = 2.20 lbs
What is 6.38 lbs?
Trailing zeros are _________________
What is significant only if a decimal point is present.
There are three isotopes of silicon. They have mass numbers of 28, 29, and 30. The average atomic mass of silicon is 28.086amu. Which isotope is most abundant?
What is Si-28?
Ca3(PO4)2
What is calcium phosphate?
The charge of an atom
What is protons - electrons?
3 cents/day = ____dollars/year
What is 10.95 dollars/year?