Unit 2 – Chapter 2Chemistry

Matter – ________________________________________.

Mass - the amount of matter an object has.- ___________________________. Gravity has an

impact on weight.- The same mass on the earth

would weigh less on the moon because less gravity on moon.

Elements – _____________________ – cannot be broken down into simpler types of matter. Examples: oxygen, carbon, hydrogen, and nitrogen – these four make up more than 90% of the mass of all living things!

Periodic Table :- Displays elements in an

organized manner.- From left to right – general

trend is toward larger sized atoms.

- See page 31 in textbook.

See page 31 in textbook:Atomic Number =

_____________________________.Atomic Mass =

______________________________________________________________________.Atom – ______________________________that

______________________________.

Atomic Structure consists of:

1. _________ = central core – consists of ______ (+) and _________ (0).

NOTE: #of protons or atomic number determines the atom’s identity.

2. _________ (-) orbit in energy levels or “shells” around the nucleus.

NOTE: # of protons = # of electrons to give an atom a net charge of zero.

3. 1st Shell (closest to nucleus) – holds 2 electrons (e-)…..these are the lowest energy electrons.

4. Each shell after the 1st can hold up to 8 electrons(e-)…..higher energy e-’s.

NOTE: In most elements, the outer shell is not filled. This determines the reactivity of the atom. See page 32 in textbook.

Compound – ______________________________________________. Exs.) water – H₂0, ammonia –

NH₃, glucose – C₆H₁₂O₆.

Isotopes – ______________________________________

________________________ it has.Ex.) C₁₂ and C₁₄ (radioactive and unstable)

Chemical Formula – shows the kind and proportion of atoms in a compound. Ex.) H₂0

Chemical Reaction – chemical bonds are broken, atoms rearranged, and new bonds formed.

Molecule – _____________________________________

_______________________________of the substance and can exist in a free state.

Exs.) O₂, O3 H₂O, CO₂, DNA, protein.See page 33 in book for bonding info:

Covalent Bonds – _____________________________Ex.) H₂O – atoms are striving for stability

Ionic Bonds:Ion = atom with a + or – charge from

_____________________________________.Ionic Bond – occurs when

______________________________________________. Ex.) NaCl – salt.

Energy – _____________or cause change. Energy can change forms. Ex.) electrical can change to radiant and thermal (light bulb).

Free Energy – energy available to do work.

__________________– solid, liquid, gas….depends on the motion of molecules. Ex.) Water – temperature makes molecules move at different rates and turns water to solid, liquid, or gas.

Energy and chemical reactions:CO₂ + H₂O ↔ H₂CO₃↑ ↑ ↑_________ __________

Activation Energy – energy needed to start a reaction. (see graph on page 37 in textbook).

Exergonic Reactions – involve a net ______________________________. Ex.) Sugar → CO₂ + water + energy.

Endergonic Reactions – involve a net _____________________________. Ex.) CO₂ + water + sunlight → sugar.

Catalyst – _______________________________________

____________________. Ex.) ENZYMES act as catalysts. (see enzyme deficiency on page 37 in textbook.

Reduction-Oxidation Reactions (REDOX reactions):

- Oxidation – reactant __________________and takes on a positive charge.

- Reduction – reactant __________________ and takes on a negative charge.

- Ex.) Na⁺ + Cl⁻ → NaCl (ionic bond)

Solution – a mixture in which _________________________________________…..can be liquids,

solids, or gases. Ex.) Blood = iron, water, oxygen, sugar, wastesSolute – a ____________________ in the solution.Solvent – a

_____________________________________.Concentration of Solution – the amount of

solute dissolved in a fixed amount of solution. Ex.) 2% saltwater = 2grams salt in 100ml water.

Saturated Solution – ____________________________________________________….the solution is

“saturated”.

Aqueous Solution – solutions in which _______________

_____________ …..very important to living things as we are made up of lots of different aqueous solutions. Exs.) blood, urine, lymph, spinal fluid, mucus.

Acids and BasesDissociation of Water – force of attraction

between water molecules cause them to break apart.

Pure water is neutral - # of OH⁻ and H₃O⁺ ions are equal.

Acid - ___________ions is greater than OH⁻ ions.

Ex.) Hydrogen chloride gas in water:

HCl ↔ H⁺ +Cl⁻ H⁺’s make the water acid.

Bases (Alkaline) - #of _________is greater than H₃O⁺ ions. Ex.) Sodium Hydroxide dissolved in water: NaOH ↔ Na⁺ + OH⁻ OH⁻ ions make the water basic or alkaline.

pH Scale – compares the relative concentrations of OH⁻ and H₃O⁺ in a solution.

pH – change in 1 pH unit = tenfold change in acidity/alkalinity. See figure 2-10, page 42 in book.

Buffers – ________________________________________

___________________________________________.

Complex Buffering Systems – maintain pH values of your many body fluids and tissues. See figure 2-10 0n page 42 in your book.