Periodic Table 1
The electrons in the outer energy level
What are valence electrons?
An atom with a negative charge
What is an electron? Who discovered it?
The atomic number tells you
What is the number of protons (and electrons) an atom of an element has?
An atom with a positive charge. Rutherford
What is a proton? Who discovered it?
A subatomic particle with no charge/chadwick
What is a neutron? Who discovered it?
The location of protons and neutrons.
What is inside the nucleus?
An atom with a completely full outer most (valence) energy level is this.
What is nonreactive also known as the Noble Gases
heavier versions of the same element; different number of neutrons/same number of protons
What are isotopes?
Volta
Who invented the first battery?
The location of electrons.k =2 ; L= 8 M = 8 or 18
What is outside the nucleus? identify the shells and the total electrons for each
Atomic mass - Atomic number
What is the formula for finding the neutrons of an atom?
8
What is the maximum number of electrons the 2nd orbital, or energy shell, can hold?
Rows on the periodic table; energy levels/shells
What are periods? What do they tell us?
Columns on a periodic table
What are groups?
Elements in the same group share this.
What are has same number of valence electrons
atomic mass and chemical properties
What Mendeleev organized the periodic table according?
The alkali metals = 1 valence electron
The alkaline earth metals= 2 valence electrons
Name the first two chemical families
how many valence electrons?
The majority of the elements on the periodic table are this.
What are metals?
Alkali and Halogens- to fill their outer shells- valance electrons
Alkali - one
Halogens - 7
What are two families that bond easily? Why?
The three classes of elements are these. metals make up left side and 90% of elements; nonmetals are on the right side; metalloids form a zigzag
What are metals, metalloids, and nonmetals? Identify their locations based on periodic table
what is the difference between the decimal mass and the whole number mass of an element?
Mosely; protons
Who organized the periodic table according to atomic number?
What did he say increases periodically?
Elements in group 1 have only 1 valence electron and are considered this; NaCl; they want to fill their outer shells
What are elements that are considered extremely reactive? Why? Give an example of a compound they form
The nucleus of the U-235 atom contains 92 protons and 143 neutrons, giving an atomic mass of 235 units. The U-238 nucleus also has 92 protons but has 146 neutrons – three more than U-235 – and therefore has a mass of 238 units. U-235 is the main fissile isotope of uranium. 238 is more abundant
What is the difference between Uranium 235 and Uranium 238?
Alkali- 1
Alkaline Earth -2
Tranisition Metals- no pattern
Halogens - 7
Noble Gases- 2 or 8
Name the families and the valance electrons for each