Vocabulary
the vertical column in the periodic table
Group
Potassium with a mass number of 40 in Hyphen form.
Potassium-40
When did JJ Thomson first make his atomic model?
1904
What is the atomic symbol for magnesium?
Mg
What does a Bohr model represent?
Structure of an atom
Particles that differ in number between isotopes
Nuetrons
explain what isotopes are.
Isotopes are atoms with the same number of protons but with different number of neutrons. They share almost the same chemical properties, but differ in mass and therefore in physical properties.
When and who created the first periodic table?
Dmitri Mendeleev created the first period table in 1869.
What is the period 1 element used to make balloons float?
Helium.
The particle located outside the nucleus of an atom.
Electron
Region surrounding the nucleus where electrons are found
Electron cloud
Explain the difference between mass number and average atomic mass.
The mass number is the sum of the number of protons and neutrons in an atom. It is a whole number. The atomic mass is the average number of protons and neutrons for all natural isotopes of an element.
How many elements were in Mendeleev's first periodic table?
63 elements
What is the only metalloid in period 3?
Silicon
An atom has a full first and second energy level and 8 electrons in its third level, what element is this atom?
Argon (Ar)
All elements in the same one of these have the same number of energy levels in their electron cloud
Period
How do you find the most common version of an element?
You can find the most common version of an element by rounding the atomic weight found on the periodic table of elements to the nearest whole number.
What experiment is Ernest Rutherford known for?
Gold foil experiment
What is the atomic mass of Bismuth?
209
What’s a valence electron?
Electrons in the outermost energy level
Smallest known Particle that makes up protons and nuetrons
Quarks
Atomic #- 92
# of protons- 92
# of neutrons- 143
write this atom in Hyphen and Nuclear form
Uranium-235
235 U
When did Democritus name the atom?
400 BC.
What are the names of the two elements with the atomic numbers 57 and 89?
Lanthanum and Actinium.
The inner most energy level has a maximum of how many electrons?
2