Introduction To Chemistry

BMS181 Subject Learning Outcomes (SLOs)

• Upon successful completion, students are expected to communicate anatomical & physiological concepts with specific terminology & illustrations.
• Students should be able to describe common disease-causing microorganisms, their classification, & how infection is transmitted & may be controlled.
• Students should be able to describe the structure & function of biological molecules, cells, & tissues.
• Students should be able to identify & describe structures and features of the integumentary systems & explain their function
• Students should be able to identify & describe the principal structures & features of the nervous system, its sub-divisions & neurophysiological processes associated with communication within the body
• Students should be able to identify & describe the principal structures & functions of the musculo-skeletal system, muscle contraction & movement, & explain bone development, growth & remodelling and the physiology of muscle contraction

Key Objectives

• Matter and its four states should be clearly defined with their properties
• Define and tell the difference between atom, element, compound and molecule
• Atomic number (Z) and atomic mass (A) must be clearly defined
• You must be able to determine the atomic number (Z) and atomic mass (A) using the first 20 elements on the periodic table
• The four main types of chemical bonds should be stated
• List the major elements and minerals found in the human body
• Define mole and Avogadro's number and relate them to atomic mass (A)

Matter

• Includes everything that occupies space and has mass
• Chemistry deals with matter, its transformations, and the energy that is released and absorbed
• Most processes that allow the body to live and function involve some kind of chemistry

States of Matter

• Matter can exist in different states, defined by distinct properties
• One way to change the state of matter is by adding or taking away heat (energy)
• Water can exist as a solid (ice), a liquid (water), and a gas (steam or humidity)
• The fourth state of matter, plasma, is most commonly found inside a star and can be ignored
• Changing state doesn’t change the chemical compound
• The states of matter have common properties or characteristics that don’t depend on the chemical they are made of
• The amount of mass that fits into a standard volume is density
• Volume is how much space something takes up
• Solid water (ice) is less dense than liquid water, unlike most substances

Atoms and Elements

• Matter can be divided into atoms.
• Atoms come in different types, each defining an element
• Elements each have very specific properties
• For example, DNA is made of carbon (black), oxygen (red), hydrogen (white), nitrogen (blue), and phosphorus (yellow) atoms

Compounds and Molecules

• Atoms combine through different kinds of bonds
• Two hydrogen atoms bind to an oxygen atom to form water (covalent bond)
• Oxygen and hydrogen are elements; water is a compound and a molecule
• Water molecules bind weakly via hydrogen bonds, causing surface tension
• Compounds have new properties that are different from the properties of their constituent elements
• Compounds and molecules are formed through chemical reactions
• A compound is used for chemicals that contain more than one element
• A molecule is used for chemicals where atoms are joined by covalent bonds

Periodic Table

• Elements grouped with similar properties are arranged in the periodic table
• Each element has a chemical symbol and atomic number
• The elements essential for all life have a black background on the periodic table

Elements in the Human Body

• Oxygen (O), Carbon (C), Hydrogen (H) and Nitrogen (N) are the most common elements in our body by weight
• Much of the oxygen and hydrogen are found in water
• Carbon forms the backbone for most molecules, including DNA, proteins, fats, and sugars
• Oxygen, hydrogen, nitrogen, phosphate, and sulphur can bind to carbon and each other
• Calcium, phosphorus, and oxygen form hard crystals for bone strength.
• Sodium, potassium, and chloride are electrolytes that affect fluid homeostasis and help muscles and nerves to function
• Magnesium, calcium, and iron are crucial for various body functions, mostly stored, and their levels are tightly controlled by blood

Atomic Mass and Moles

• Atomic mass can be used to determine how many atoms or molecules are in a weighed quantity.
• The counting unit for atoms and molecules is the 'mole'
• Reading the atomic mass from the periodic table is simple
• 1 mole of carbon atoms weighs exactly 12.01 grams
• 1 mole of oxygen atoms weighs exactly 16.00 grams
• A mole is a number, like a dozen
• Avogadro's number is 6.022 x 1023
• Therefore, one mole is 6.022 x 1023 atoms
• A mole is a standard unit for measuring large quantities of very small entities, the amount of material containing 6.02 x 1023 units of the measured substance
• We use moles to count atoms and molecules because they weigh different amounts

Molecular Weight

• The molecular weight of a compound is the weight of its atoms
• Find the atomic mass of the atoms in the periodic table and add them together, to discover how much a mole of ethanol weighs
• The molecular weight of ethanol is 46.1
• One mole of ethanol weighs 46.1 grams