The Chemistry Of Life

Matter Everything in the universe is made of matter Matter is anything that occupies space and has mass Weight varies Your weight would be a different weight on the moon This is because the moon exerts less force than the earth

Matter Chemical changes in matter are essential to all of life's processes By learning how changes occur, we can start to understand life

Elements and Atoms Elements are substances that cannot be broken into simpler kinds of matter Elements are commonly found in the periodic table of elements This chart organizes the over 100 elements into categories

Elements and Atoms The periodic table gives every element a chemical symbol It consists of one, two or three letters The letters are related (normally) to the chemicals name in English or Latin

Elements and Atoms The smallest or simplest particle of an element that retains all properties of that element is an atom The compisition of an atom give elements their properties

Elements and Atoms Atoms are so small there is no way for us to see them clearly However, we can test the properties of the atom to get a better idea of how they are built

The Nucleus The center region of an atom is a nucleus It makes up the bulk of the mass of an atom Made of two parts… The proton is positively charged The neutron is neutrally charged

The Nucleus The number of protons in an atom is called its atomic number This can be found in the periodic table of elements The atomic number directly relates to the number of protons

The Nucleus The atomic mass of an atom is equal to the total number of protons and neutrons This is also in the periodic table

Electrons Electrons are negatively charged particles that are outside the nucleus In an atom, the number of positively charged protons is balanced by electrons This means the net charge on an atom is 0

Electrons Electrons are found in orbitals An orbital is a three dimensional region around a nucleus that indicate a probable electron location When all orbitals are looked at, it looks like a cloud of electrons

Electrons Orbitals correspond to different levels of energy Certain orbitals can only hold a set number of electrons The first orbital can only hold two electrons The second orbital can hold eight electrons

Isotopes All atoms of an element have the same number of protons They don’t all have the same number of neutrons Elements with the same number of protons and different numbers of neutrons are called isotopes

Isotopes The different numbers of neutrons change the mass of the element This means it still basically acts like an element, but it behaves a bit differently The average atomic mass factors in the amount of isotopes