Module 1
Convert 500mL to Liters.
0.5 L
What is the main difference between a chemical and physical change?
A chemical change requires the production of a new substance, which occurs when the atoms involved are rearranged and form new compounds.
How many electrons does a Helium atom have?
2
Which subatomic particle is responsible for an element's chemical properties?
electrons
What are the Group 1 elements called?
Alkali Metals
4 (all, due to the decimal point)
How do you find the mass number of an atom?
protons + neutrons = mass number
How many protons, neutrons, and electrons does an aluminum atom have?
13 protons, 13 electrons, 14 neutrons
3.0 x 108 m/s
Which family of elements is nonreactive?
Noble Gases
A city's population is counted as 976,431. Round this population to 3 significant figures.
976,000
What type of mixture does not blend smoothly together in which the individual substances remain distinct? (example: salad dressing)
Heterogeneous mixture
An isotope is a version of an atom with...
a different number of neutrons than usual
A wave traveling at a frequency of 4.5 x 10-13 has a wavelength of...
speed / frequency = wavelength
6.7 x 1020 m
What periodic trend describes an atom's "desire" to gain more electrons?
Electron Affinity
A weather forecast predicts that there will be 1.5 inches of rain tomorrow, but when the rain actually stops, the total rainfall is measured to be 1.2 inches. What is the percentage error of the weather forecast?
error = 0.3 inches.
0.3 / 1.2 = 0.25
0.25 x 100 = 25%
What do you call the substances at the start of a chemical reaction and the substances at the end of a chemical reaction?
Start = reactants
End = products
What were the findings of Rutherford's Gold Foil Experiment?
1) There is a positively charged nucleus in the center of the atom
2) The nucleus is surrounded by empty space (minus the electrons)
What is the energy of a photon from the violet portion of the Sun's light if it has a frequency of 7.230 x 1014 s-1?
Planck's Constant x Frequency = (6.626 x 10-34 Jxs)(7.230 x 1014 s-1)
4.791x10-19 J
What is an ion?
An atom with a different amount of electrons
What is the product of 6.02 x 1023 and 0.0045, rounded to the correct number of significant figures?
2.7 x 1021 (Rule: you only keep two sig figs because 0.0045 only has 2 sig figs)
C6H12O6 is the molecular formula for glucose. What is the percent by mass of carbon?
40%
Element X exists as 2 isotopes, 6X (6.015amu) and 7X (7.016amu). Their percent abundances are 7.59% and 92.41%. Calculate its average atomic mass.
6.9425amu
Record the electron configuration for Arsenic and record its quantum number for the highest electron.
[Ar] 3d¹⁰ 4s² 4p³
[4, 1, 1, +1/2]
What is the most reactive metal and the most reactive nonmetal?
Metal = Francium
Nonmetal = Fluorine