Chemistry
What is the mass number of an element?
protons + neutrons
In an experiment what is the variable you change in order to see what happens?
Independent Variable
What element has the following electron configuration: 1s2 2s2 2p6 3s1
sodium
In order for two electrons to occupy the same orbital, they must:
have opposite spins
Visible light, X-Rays, infrared radiation, and radio waves all have the same:
speed
Isotopes are atoms of the same element that have different:
number of neutrons
The three types of nuclear radiation in increasing order of penetrating power are:
alpha, beta, gamma
Rutherford’s experiments led him to conclude that atoms contain massive central regions that have:
1) positive charge
2) negative charge
3) no charge
4) protons and electrons
positive charge
The average distance between the Earth and the moon is 386,000 km. What is this in scientific notation?
3.86x10^5 km
The atomic number of fluorine, 9, indicates that there are nine:
protons
The mass of an 11 g sample of clay has a volume of 5.00 cm3. What is the density of the clay?
2.2 g/cm^3
An atom is electrically neutral because?
protons and electrons are equal
The electron configuration for aluminum (atomic number 13) is:
1s2 2s2 2p6 3s2 3p1
What happens for an electron to go from ground state to an excited state?
Absorbs energy
A paperclip is 3.20 cm long. How many inches long is the paper clip (1 in = 2.54 cm)
1.26 in
The region outside the nucleus where an electron can most probably be found is the
electron cloud
What is the energy of a wave with a frequency of 5.88 x 10^17 Hz?
3.90x10^-16 J
Complete the alpha radioactive reaction for 14/6 C
14/6 C---> 10/4 Be + 4/2 He
7.0x10^5 / 3.5 x 10^2 (be careful with your answer)
2.0x10^3
List these in order of largest to smallest:
m
km
mm
cm
km, m, cm, mm
If light emitted off of an object has a wavelength of 547 nm, how many meters? (1 m = 10^9 nm) (1nm= 1x10^-9m)
What is the frequency?
5.48x10^14 Hz
A reaction was predicted to produce 50.0g of product, but only 42.0g was actually collected. What is the percent yield? Use correct sig figs.
84.0%
An element has two isotopes (X and Y) that are outlined in the following chart. Calculate the atomic mass
X- mass=106.905, % abundance= 52%
Y- mass= 108.905, % abundance= 48%
107.87 amu
Given: atomic #=16, # neutrons =20, electrons =18
Find: element, atomic mass, charge
Sulfur (S)
mass=36
charge=-2
A block of wood has dimensions 5.0 cm × 3.0 cm × 2.0 cm. Its mass is 45 g. What is the density?
1.5 g/cm^3