Significant Figures
How many significant figures are in 45.2?
3
What subatomic particle has a positive charge?
Proton
Who first proposed the idea that matter was made of tiny particles called atoms?
Democrituis
How many centimeters are in 2 meters?
200 centimeters
What is mass number?
number of protons plus neutrons
How many significant figures are in 0.00450?
What subatomic particle has no charge?
Neutron
Which scientist developed an atomic theory based on experimental evidence?
John Dalton
Convert 350 cm to meters.
3.5 meters
Write 6.2 × 10⁻⁴ in standard notation.
0.00062
Calculate 4.56 × 2.1 and give the answer using correct significant figures.
9.576= 9.6
An atom has 12 protons and 13 neutrons. What is its mass number?
25
Which scientist discovered the electron using the cathode ray experiment?
What is the conversion factor for inches to centimeter?
1 inch=2.54 centimeters
What is an isotope?
Element with the same number of protons but different number of neutrons
Calculate 15.67 + 2.3 + 4.125 using correct significant figures.
22.095= 22.1
An atom has 17 protons, 18 electrons, and 18 neutrons. What is its overall charge?
-1
Which scientist discovered the proton?
Eugene Goldstein
Convert 2.5 kg to grams.
2,500 grams
How do hydrogen-1 and hydrogen-2 differ?
They are isotopes of one another so they have different neutrons.
Calculate (12.45 × 3.2) ÷ 1.50 using correct significant figures.
26.56= 27
An ion has 20 protons, 18 electrons, and 22 neutrons. Determine its atomic number, mass number, and charge.
Atomic Number: 20
Mass Number: 42
Charge: +2
Which scientist discovered the neutron?
James Chadwick
What is the conversion factor of miles to feet?
1 mile= 5280 feet
Element Z has two isotopes: mass 19.0 at 55.0% abundance and mass 21.0 at 45.0% abundance. Calculate its average atomic mass.
19.9 amu