History of Chemistry
Early people were producing these types of changes even though they didn't know what was happening. For example - extracting metals from ores and making jewelry.
chemical changes
What are the three subatomic particles.
Protons, neutrons, electrons
If an atom was enlarged so the electrons were spinning around the stands of a football stadium, how big would the nucleus be?
marble, grape, small pebble
This is anything that takes up space (has a mass).
matter
Atomic numbers of an atom are the same as the number of what in an atom?
protons
Who developed the periodic table of elements.
Dmitri Mendeleev
These particles have a positive charge and are found inside the nucleus.
proton
Atomic masses are measured in what?
AMU
The smallest pieces of matter are called __________.
atoms
Name three isotopes found in nature
Carbon-12. Carbon -13, Carbon-14
The earliest form of chemistry was called _______.
alchemy
These particles are located within the nucleus, and have no charge.
Neutron
A proton has the atomic mass of what?
1 amu
What is the number above each element and what does it tell us?
it is the atomic number and it tells us how many protons an element has.
What element has a number of 56?
barium
Names for elements comes from the English or __________ name.
latin
These particles are negatively charge and are found outside the nucleus.
electrons
A neutron has the atomic mass of what?
1 amu
How do we know the number of electron shells are surrounding an atom?
Look at the period number.
Why does hydrogen have an atomic number of 1?
because it only has one proton
Who first realized that an atom had a nucleus?
Ernest Rutherford
Most of the mass of an atom is located here.
nucleus
An electron has a mass of what?
1/1836 or .000544
What is the name for an element that has a different number of neutrons than protons?
isotopes
If an atom gains four electrons what is the new charge and WHY?
-4 because it gained four electrons giving it four more negative charges than the protons.