Significant Figures
How many significant figures are in 0.0023 g?
2 sig figs
What state of matter has a definite volume but no definite shape?
Liquid
How many atoms is in one (1) mole of oxygen?
6.022 X 1023 atoms
What is the name for the negatively charged part of an atom?
Electron
Which chemist theorized that all matter is made of small indivisible particles (called atoms)?
(John) Dalton
What is 10.2496 mol rounded to 4 significant figures?
10.25 mol
What state of matter has strong cohesive forces and relatively low kinetic energy?
Solid
What units are used for molar mass?
g/mol
What is the name for the positively charged center of an atom?
Nucleus
What man theorized that equal volumes of gas under the same conditions will contain equal numbers of molecules?
(Lorenzo Romano Amadeo Carlo) Avogadro
How many significant figures will be in the final answer?
0.432 x 1.262
(you do NOT have to solve the equation)
3 significant figures (0.545)
Is 20 g of CO2 a mixture or a pure substance?
Pure Substance
What is the molar mass of H2SO4?
98.072 g/mol
How many protons does lead have?
82 protons
What chemist determined that atoms have negative and positive components?
(J.J.) Thomson
How many significant figures will be in the final answer?
21.796 - 0.10
4 sig figs (21.70 = 21.696 -> two decimals)
What state of matter does NOT take the shape of its container?
Solid
How many moles are in 12 g of Helium?
~3 moles
How many electrons are in Be2+?
2 electrons
What chemist determined that atoms have a central nucleus containing positive charge and randomly distributed negative charge?
(Ernest) Rutherford
What is 53,983 rounded to 3 significant figures?
5.40 x 104
What is the name of the process in which a solid turns directly into a gas?
Sublimation
How many grams is 5.747 x 1023 molecules of N2O?
42 grams
How many neutrons are in carbon-14?
8 neutrons (= 14 - 6)
What scientist's experiment measured the charge of an electron?
(Robert) Millikan