CHem Flashcards
Atom
Smallest unit of matter that can occur naturally
Compound
Two or more atoms chemically bonded together
Element
Made of one type of atom
Atomic Number
The number of protons in the nuculeus. Also called the Proton Number
Mass Number
The mass of the atom Also called the “Nucleon Number”
Electron Arrangement
Electrons are arranged in energy levels around the nucleus
Valence Electrons
The electrons located in the outermost energy level of the atom
Periods
Horizontal Rows, Periods tell the number of electron energy levels
Where are Non Metals annd Metal elements on the periodic table
Metal Elements: Left
Non-Metal Elements: Right
Staircase on the Periodic table
Groups
Vertical Columns, Tell number of valence electrons in the atoms
Characteristics of Alkali Metals
Soft
Low density
Low melting and boiling point
Reactive
As you go down the group the reactivity increases
Left most Column on The Periodic Table
Characteristics of Alkali Earth Metals
Good Conductors
medium hardness and density
medium reactivity
Top row of the bottom two on the Periodic Table
Characteristics of Transition Elements
Hard Dense
High Melting point and boiling
not very reactive
Form colored compounds
can vary in their number of valance electrons
used in making Alloys
Used as a catalyst in chemical reactions
Middle of the Periodic Table
Alloys Definition
Mixtures of metals to make them stronger or corrosion resistant
Catalyst
Chemicals that speed up reactions
