Atoms are made of protons, electrons, and neutrons. Protons and neutrons are located inside the nucleus that is at the center of an atom. Electrons occupy orbitals, which are located outside the nucleus. In this module, you will study the structure of atoms.
Atoms are the building blocks of matter. Every living and non-living thing is made of atoms. Those same atoms make up elements. For example, gold is an element and is made of gold atoms.
Atoms are the basic building blocks of matter that make up everyday objects. A desk, the air, even you are made up of atoms!
There are 90 naturally occurring kinds of atoms. Scientists in labs have been able to make about 25 more.
Protons- carry a positive charge -1 amu= heavy
In 1968 new particles were discovered inside the proton called quarks.
There are 3 quarks in each proton and gluons hold them together
Neutrons carry no charge- discovered in 1932- also have quarks and gluons
Protons and neutrons join together to build the nucleus- the central part of the atom
Electrons carry a negative charge and circle the nucleus- electrons are extremely small and very light
Electrons are easy to strip off an atom and use for electrical power
Electrons can tell about the inside of an atom atomic number = number of protons isotopes mass number = number of protons+ neutrons s=1 p=3 d=5 f=7 each orbital can hold 2 electrons
2n^2 can be used to calculate the max number of electrons in the nth level
Orbitals are regions where electrons are likely to be found

The periodic table is an organized list of all the elements known to us. It contains key information about the elements such as atomic number, atomic mass, symbols, names of the elements, relative sizes of atoms, reactivity and more. It is an essential chart that chemists cannot do without. In this module you will learn the organization of the periodic table.
Columns-= groups
Rows=periods

The first column of the periodic table is the group of elements known as the Group 1 or alkali metals. This group includes lithium, sodium, potassium, rubidium, cesium, and francium. By definition, a metal is an element that loses one or more electrons to create a positively charged ion known as a cation (pronounced "cat"- "ion")
The second column of elements from the left of the periodic table is known as the Group 2 or alkaline earth metals. It consists of beryllium, magnesium, calcium, strontium, barium, and radium.
The group of elements at the far right of the table (Group 18) is known commonly as the noble gases. They are generally chemically inert. This means that they do not react with other elements because they already have the desired eight total s and p electrons in their outermost (highest) energy level. The elements in this group are helium, neon, argon, krypton, xenon, and radon. They are monatomic gases.
Group 17 is a family of elements known as the halogens. The word "halogen" means "salt-former." The halogens form salts when they react with a metal. Halogens exist in a variety of states at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids.
Group 16 is the oxygen family. It consists of the elements oxygen, sulfur, selenium, tellurium, and polonium.
The Group 15 elements are generally known as the nitrogen family. All of the elements of this family have five electrons in their outermost energy level. This group is divided into nonmetals, semimetals, and metals by characteristic. The top two elements, nitrogen and phosphorus, are very definitely nonmetals, forming -3 charge anions. Nitrogen is a diatomic gas and phosphorus is a solid. The elements arsenic, antimony, and bismuth all have some characteristics of semimetals such as brittleness as a free element.
Group 14 is the carbon family. The five members are carbon, silicon, germanium, tin, and lead.
The last of the p block families we will be looking at is the boron family -- Group 13. This