Elements of the Periodic Table
The first element in the periodic table that has an atomic number of 1.
Hydrogen
He is the Russian chemist who developed the basis of the modern periodic table.
Dmitri Mendeleev
What are a set of elements sharing common properties called?
An element family
The periodic table is arranged in this order.
Increasing atomic number
These particles are also called "helium nuclei."
Alpha Particles
Phosphorus (P) has this atomic weight.
30.9 AMUs
Mendeleev organized his table by increasing _______.
Atomic Mass
These are the very reactive set of elements that are found in group 1.
Alkali Metals
Atomic radius _______ as we go from left to right on the periodic table.
Decreases
Electrons
This element has an atomic weight of 83.8 AMUs.
Krypton (Kr)
Mendeleev left blank spaces in his table for ___________.
Undiscovered elements
These gases in group 18 are inert.
Noble Gases
This is the most common category of element on the periodic table.
Metals. There are around 90 metals in the periodic table.
This term is used for spontaneous release of energy or particles from an unstable atom.
Radioactivity
______, an element with atomic number 10, is a noble gas.
Neon (Ne)
This particle determines an elements identity and atomic number.
Proton
This category of element is usually not shiny, brittle, and a poor conductor of electricity.
Nonmetals
In the periodic table, the ________ sit between the transition metals on their left, and the metalloids on their right.
Post-Transition Metals
Beta radiation can be blocked by this material.
Aluminum foil.
What is the atomic number of the element (Oganesson - Og)?
118
This Greek philosopher proposed that matter was made of indivisible particles he called atomos.
Democritus
A set of elements whose radioactivity is their most unique trait. Because of their unstable nucleus, they decay into other elements and other simple particles.
Actinides
Electronegativity _________ as we go down the periodic table.
Decreases
Paper can block this type of radiation.
Alpha