Ions I
What is the charge on gallium ion?
+3
What is the charge on oxide ion?
-2
How many protons in a carbon-13 atom?
6
How many neutrons does a sulfur-33 atom have?
17
The electron.
What result did Rutherford not anticipate when he shot alpha particles at a thin layer of gold foil?
That some of the alpha particles would experience significant deflections rather than passing straight through.
Name this ion: S2-
Sulfide ion.
Name this ion: Ca2+
calcium ion
How many neutrons in 71Ga?
40
How many neutrons in 123Sb?
72
Name the 4 scientists associated with the 4 models of the atom we studied in this class.
Why is the "plum-pudding model" a misleading name for Thomson's picture of the atom?
The electrons are not actually embedded in the positive medium. They can move about.
46
How many electrons in iron(III) ion?
What differs when you compare two isotopes of the same element?
The number of neutrons.
The isotopes of an element have the same ________ number but different _________ numbers.
atomic, mass
What is one way Rutherford advanced our understanding of the atom from Thomson's picture?
1) He proposed that the mass of the atom was concentrated in a positively-charged nucleus.
2) The atom's electrons orbited the positively-charged nucleus.
Loosely (and briefly) describe the purpose of using scientific models.
They help us understand a small piece of what is happening in reality (but do not capture all of the complexity involved).
What is a negatively charged ion called?
An anion.
Which elements on the periodic table have a full valence shell?
The noble gases.
Explain why the mass number of an isotope is always a whole number but the atomic mass is typically a decimal.
The mass number only counts the number of protons and neutrons in the nucleus. The atomic mass from the periodic table is an average of the masses of the different isotopes, weighted by their percent abundance in nature.
What is the mass of a carbon-12 atom (in amu)?
Describe the structure of an alpha particle.
What is one way the Bohr model advanced our understanding of the atom?
Two possible answers:
1) Electrons are arranged in energy levels rather than orbiting anywhere about the nucleus.
2) Each energy level could only contain a specific number of electrons.
Why might atoms tend to form ions?
They are in a lower energy state when they achieve the same electron configuration as a noble gas.
Strontium ion has the same electron configuration as which noble gas?
krypton
Boron has two stable isotopes: boron-10 and boron-11. Which isotope is more abundant in nature and why?
The periodic table lists boron's atomic mass as 10.811 amu. Since the weighted average atomic mass is closer to 11 amu than 10 amu, we would expect boron-11 isotope to be more abundant.
What is the difference between a stable isotope and a radioactive isotope?
The stable isotopes do not change over time. Radioactive isotopes may decay into other elements, emitting particles and radiation in the process.
Describe Dalton's picture of the atom (2 points).
1) The atoms were small spheres.
2) Atoms of the same element would have the same properties.
3) Atoms of different elements would have different properties.
Which observations led to Bohr concluding that atoms have different energy levels?
Atoms could not absorb or emit just any amount of radiation, only very specific amounts.