Basic Chemistry
Ms. Foster | FS Unit 3
Why we need to understand chemistry…
• To understand why ingredients react the way they do in recipes or
formulations.
• Chemistry – the study of the make-up, structure, and properties of
substances and the changes that occur to them.
• It is the study of matter
• Matter – anything that occupies space and has mass
Atoms
• Everything you encounter is made of Atoms (animals, plants or
minerals)
• Atom – the smallest unit of any elemental substance that maintains
the characteristics of that substance.
• Ex: one atom of iron has the same physical characteristics as a chunk of iron.
• Atoms are extremely tiny
• Subatomic Particles are the smaller particles that make up an
atom.
Atoms Continued
• Nucleus – central core of the atom, contains tightly clustered particles
of protons and neutrons
• Proton – subatomic particle that has a positive electrical charge.
• Neutron – a subatomic particle that is electrically neutral
 Protons & Neutrons have the same mass
Atoms Continued
• Electrons – have a negative electrical charge that is equal to, but opposite, the positive
charge of a proton.
 Have a much smaller mass than protons and neutrons.
• It takes aprox. 1,836 electrons to equal the mass of one proton.
• The reaction between the positive and negative charges of protons and electrons cause
the electrons to spin around the nucleus.
• Electrons prefer to move in pairs and the space that is occupied by a pair of electrons in an
atom is called an orbital.
Parts of an Atom
Elements
• An element is a substance that contains only one kind of atom
• There are about 90 naturally occurring elements known on earth.
• All matter on earth is composed or one or more elements.
• Scientists have use these to create approximately 27 additional elements.
• The number of protons in the nucleus determines which element an atom is
o Pure oxygen is composed of atoms with 8 protons in the nucleus.
o Calcium (one of main components of bone tissue) composed of atoms with 20 protons in each
nucleus.
Periodic Table Overview
• Atomic Number – the number of protons in the
nucleus of each atom of the element.
• Atomic Mass – equal to the sum of the masses of
protons and neutrons in an atom.
Works Cited
• Ward, Janet. Principles of Food Science. Third ed. Goodheart-WIllcox.