Atom and Atomic Theory
What is the basic unit of matter?
The atom
Where are electrons located in an atom?
In the electron cloud or orbitals around the nucleus.
Who created the first periodic table?
Dmitri Mendeleev
Are metals good conductors of electricity?
Yes
What is a mixture?
a combination of two or more substances that are not chemically combined
What are atoms made of?
protons, neutrons, and electrons
Are electrons positively or negatively charged?
negatively charged
Elements are arranged in order of increasing what?
atomic number
Which property is typical of metals: brittle or malleable?
malleable
How is a compound different from a mixture?
In a compound, substances are chemically bonded, whereas in a mixture, they are not.
What subatomic particle has a positive charge?
A proton
How many electrons can the first energy level hold?
2 electrons
The elements in a vertical column are called what?
groups
Are most nonmetals solids, liquids, or gases at room temperature?
Gases
Give an example of a compound.
E.x. Water H₂O
In which part of the atom are neutrons located?
the nucleus
What is the octet rule?
Atoms tend to gain, lose, or share electrons to have 8 in their outer shell.
What is the atomic number of carbon?
6
Are nonmetals typically found on the left or right side of the periodic table?
the right side
In a chemical formula like H₂O, what does the "2" indicate?
The number of hydrogen atoms in water.
What is the Atomic Number?
The number of protons an element has
How many electrons are in the outermost shell of a noble gas like neon?
8 electrons
Name a periodic trend
Effective Nuclear Charge or Atomic Size
Name a metal that is a liquid at room temperature.
Mercury
In a compound, can you vary the amount of each element?
No