5.1
The periodic table categorizes what?
Elements
Atomic number represents an atoms what?
protons
most elements are classified as what?
metals
Metals are good conductors of what?
heat/ electricity
What is the direction that periods go?
left to right/ horizontal
Dmitri Mendeleev was playing what when he came up with the idea to arrange elements?
Card game/ solitaire
Elements in a group will have similar what?
chemical properties
Nonmetals generally have properties that are _____ of metals.
opposite
Group 8A elements are called what?
noble gasses
What is the direction that groups go?
up and down/ vertical
Mendeleev organized elements into rows of increasing what?
mass
Each period represents the amount of what?
electron orbitals/ energy levels
Group 7A are called what?
halogens?
The metals in groups 3-12 are called the what metals?
transition
the three ways elements are categorized are what?
metals
metalloids
nonmetals
Mendeleev was able to make predictions based on what?
mass and properties of elements
Each group is representative of what?
valence electrons/ electron configuration
Metalloids may or may not conduct electricity depending on what?
temperature
The most abundant element in earth's crust is what?
oxygen
Alkali metals' reactivity does what from top to bottom?
increases
What year did scientist Antoine Lavosier categorize the 17 known elements?
1789
Atomic mass depends on the distribution of what?
Isotopes
Name an element found in fertilizer
nitrogen/ phosphorus
magnesium plays a key role in what plant process?
photosynthesis
Aluminum is the _____ metal.
softest, most abundant