This document provides an overview of key concepts in biology and physical science, including: - Chemistry is the study of matter, physics is the study of energy and its effects on matter. Matter is anything that has mass and takes up space. - Atoms are the basic building blocks of matter. Atoms can combine to form molecules and compounds with unique properties. - The periodic table organizes the known elements based on their atomic structure. Elements combine via ionic or covalent bonds to reach stable electron configurations. - Matter exists in solid, liquid, gas or plasma states, depending on temperature and pressure. Physical and chemical properties can be observed and measured without changing the identity of the substance.

1. Biology
Physical Science Notes

2. • Chemistry – study of all forms of matter
(solids, liquids, gases, plasma)
• Physics – study of the way energy affects
matter
• Property is the ability to do something
• Can be observed or measured without
changing the matter’s identity

3. Matter
• Matter is made of atoms in motion
• Matter is anything that has mass and takes up
space (volume)
• 4 states of matter – solid, liquid, gas, plasma
• Water is the only compound that exists on earth
in all 3 states
• No 2 objects can occupy the same space at the
same time
• Inertia is a property of matter: moving doesn’t
want to stop, stopped doesn’t want to move

4. States of Matter
• Solid: either crystalline or amorphous, can not
change shape, has a fixed volume
• Liquid: particles slide past each other, change
shape, not volume
• Surface tension and viscosity are properties
of a liquid
• Gas: particles are spread out, change shape
and volume, a gas is the only state of matter
that can be compressed

5. Density/solubility
• Density is mass/volume and identifies how
tightly packed matter is.
• Water is the only substance with a density of
1g/mL.
• Density is unique to an element or a
compound.
• Solubility- the ability to dissolve at a given
temperature and pressure

6. Examples of physical properties and
physical changes
• Physical Property
• Boiling Point
• Freezing Point
• Melting Point
• Condensation Point
• Evaporation Point
• Ductile
• Malleable
• Solubility
• electric conductivity
• density
• Physical Change
• Boiling
• Freezing
• Melting
• Condensing
• Evaporating
• Stretching into wire
• Hammer into sheet
• Dissolving
• Moving electricity
• Mass/volume

7. NOT physical properties
• Never use weight, mass, volume, shape or
size to describe matter
• Weight is a measure of the force of gravity,
relative to location
• In other words, physical changes do not
change the identity of the matter

8. Chemical Properties
• Chemical property – a property of matter that
describes a substances ability to participate in
chemical reactions (you get something new)
• Examples of chemical properties
– Flammability – ability to burn
– Reactivity with acid
– Reactivity with water
– Reactivity with oxygen
– Reactivity with other elements
– Combustion (ignite, or burst into flame)

9. Evidence of Chemical Change
• Heat produced
• Cold produced
• Gas produced
• Light produced
• Odor change
• Color change
• Precipitate produced (solid)
• Oxidation (tarnish)
• Electrolysis
• Bubbling
• Foaming
• Fizzing

10. Mixtures, Solutions, Suspension, Elements,
Compounds, Acids, Bases and Salts
• Mixture: Two or more substances that are not
chemically combined
• All mixtures can be physically separated
• Ratio of mixtures are not fixed
• Mixtures can be solid, liquid or gas
• Solution: Mixture that appears to be a single
substance
• Material must be soluble (able to dissolve)

11. • Solute is what is dissolved
• Solvent what the solute is dissolved in
• Water is the universal solvent
• Solubility is the ability of substances to
dissolve at a given temperature and pressure
• Suspensions: are mixtures where the particles
are heavy enough to settle out (sink to
bottom) of the solution, scatter light, can be
filtered

12. Elements
• Elements: are pure substance that cannot be
separated into simpler substances by physical or
chemical means
• Elements can be identified by their characteristic
properties (physical and chemical)
• Elements are classified by large categories:
• Metals – shiny, good conductors
• Nonmetals – dull, poor conductors
• Metalloids –has properties of metals and
nonmetals depending on conditions

13. Compounds
• Compounds: pure substance composed of two or
more elements that are chemically combined
• Elements do not form compounds randomly
• Compounds form in specific mass ratio
• When elements form compounds, new
characteristics properties are created
• The only way to separate a compound into
elements or other compounds is by a chemical
reaction which allows for a chemical change by
adding (endothermic) or taking away
(exothermic) energy

14. Acids, Bases and Salts
• Most acids start with the element H, hydrogen
– EX: HCl (hydrochloric acid), H2SO4 (sulfuric acid)
• Any compound that increases the number of
hydronium ions, (H+), when dissolved in water is an
acid
• NEVER TASTE, SMELL OR TOUCH ACIDS
• Properties: has sour taste (think vinegar or
lemons), corrosive, react with some metals to
produce hydrogen gas, conduct electricity
• Most widely made acid H2SO4

15. • Most bases end with OH-, a hydroxide ion, when
dissolved in water
• NEVER TASTE, SMELL OR TOUCH BASE
• Properties: has bitter taste and slippery feel
(think soap), corrosive, conducts electric current
• Strong acids will have additional Hydrogen (H+)
molecules in the compound (HCl – vs- H2SO4)
• Strong bases will have additional hydroxide (OH-),
molecules in the compound (MgOH –vs- Ba(OH)2)
• 7 on the pH scale is neutral (H2O)
• Bases have a pH greater than 7
• Acids have a pH less than 7.

16. Salts
• Large group of compounds with similar
properties (usually formed with elements in
group 17, halogens)
• When a reaction occurs between an acid and
a base, they neutralize each other
• When an acid neutralizes a base, salt and
water are produced

17. Atomic Theory
• Democritus (440 BCE)- realized that if you
continued to cut something, eventually you
would end up with something that couldn’t be
cut anymore, atomos – meaning not able to
divide
• Atoms are the smallest particle that an
element can be divided and still be the same
substance
• All matter is made of atoms

18. John Dalton (1803)
• realized that atoms combine in very specific
proportions (ratios) based on mass
• all substances are made of atoms and they can not
be created, divided or destroyed because they were
made of a single substance
• All atoms of the same element are exactly alike and
different from other elements, they are unique
• Atoms join with other atoms to form new substance

20. J. J. Thomson (1897)
• discovered that there were small particles
inside the atom, meaning that atoms can be
divided into smaller substances
• Electrons – negatively charged particles
attracted to positively charged particles
• Plum pudding model – electrons are mixed
throughout the atom, soft blobs of matter

22. Ernest Rutherford (1909)
• Discovered that an atom contains a nucleus
with positively charged particles and that the
electrons must be “floating” around the
nucleus
• Most of an atom is empty space

24. Niels Bohr (1913)
• Proposed that electron moved around the
nucleus in energy levels (shells), but no
electrons between the energy level (think
ladder)
• Electrons can jump from one level to another
• Travel in a definite path

26. Modern Atomic Theory
• Erwin Shrodinger & Werner Heisenberg
• Electrons have no predictable pattern and
move in a region where electrons are likely to
be found called the electron cloud

28. Atoms
• All atoms have a nucleus
– protons (+),
– neutrons (no chg)
– electrons (-)
• Same number of protons and electrons an atom has
no charge
• More protons (+) than electrons (-) the atom has a
positive ion is formed (more positives than negatives)
• More electrons (-) than protons (+) a negative ion is
formed (more negatives than positives)

29. • 117 different element that are unique and all
things known to exist come from a
combination of these elements in specific
mass ratios
• Simplest atom is made of one proton, and 1
electron – hydrogen (has no neutrons)

30. • All additional element will have protons,
neutrons and electrons
• The atomic number of an element is
determined by the number of protons,
– 1 is hydrogen, 6 is carbon, hydrogen has 1 proton,
carbon has 6 protons (you can not change the
number of protons)
• To find neutrons take the mass number
(rounded) and subtract the protons.

31. Isotopes
• Isotopes have the same number of protons but
additional neutrons which causes the atomic mass to
be different
• Isotopes can be stable (maintain there structure) and
unstable (fall apart over time)
• Unstable isotopes are radioactive and will decay over
time giving off particles and energy (radioactive)

32. • Mass number determines the isotope, the
number of protons and neutrons added
together
• Most elements have isotopes
• All isotopes of an element have the exact
properties of the element

33. Forces in atoms
• Gravitational force – pulls objects toward each
other—depends on mass and distances
between the objects—very small force in
atoms
• Electromagnetic force –– proton (+) and
electrons (-) have strong attraction which
keeps the electrons in motion around the
nucleus of atoms

34. • Strong force – force which keeps protons from
flying apart due to close distance between
protons and neutrons
• Weak force – relevant to radioactive atoms-allows
neutrons to change into proton and
electron

35. Periodic Table
• Dmitri Mendeleev-recognized that elements
had repeating patterns (periodic) and
organized elements into a table by increasing
atomic mass
• Henry Moseley - determined that the number
of protons - atomic number (which is unique
to each element) would allow the elements to
fit into very specific pattern

36. • Separated into 3 large categories: metals,
metalloids, nonmetals based on their
properties, moving from left (very reactive) to
right (gradually becoming completely non-reactive)
across each period on the table
• Columns are called groups or family, each has
a name
• Each element in a family has the same
number of valence electrons in the outer shell

37. • Group 1 – Alkali Metals
• Group 2- Alkaline Earth Metals
• Group 3-12 – Transition Metals
• Group 13 – Boron Group
• Group 14 – Carbon Group
• Group 15 – Nitrogen Group
• Group 16 – Oxygen Group
• Group 17 – Halogens
• Group 18 – Noble Gases
• 1st Row at bottom – Lanthanides
• 2nd Row at bottom - Actinides

38. • Rows (left to right) are called periods (7 rows)-
determines the number of energy levels
• 1st energy level – 2 valence electrons (max)
• 2nd energy level – 8 valence electrons (max)
• 3rd energy level – 18 valence electrons (max)
• And so on….
• Each energy level can have less valence
electrons but they can not have more than
the maximum valence electrons.

39. Bonds – Octet Rule
• To form bonds, elements must reach a full
state of 8 valence electrons in the outermost
energy level (octet rule) (Exception: would be
first energy level which is full at 2-helium)

40. • Atomic number = Number of Protons
• Electrons equal to the number of protons
• Neutrons equal atomic mass (rounded) minus
the protons
• Protons do not change in a atom, neutrons
can change (isotopes), electrons can be shared
or transferred (when bonds are made)

41. Chemical Bonding
• Bonds are formed between elements that can
rearrange their molecules to create compounds.
• Bonds only form when energy is put in or taken
away (endothermic or exothermic)
• For bonds to form, the outer energy level must
equal 8 (octet rule) for one of the elements.
• Ionic bond – electrons are transferred (one
element gets to 8) between a metal and a
nonmetal
• Covalent Bond – electrons are shared (both
elements get to 8) both nonmetals

42. • If any atom losses electrons, the molecule
becomes positively charged ion.
• If an atom gains electrons, the molecule
becomes negatively charged ion.

43. Steps to Draw Bonds
• Determine the number of valence electrons
• Determine which elements needs what
• Draw the electron dot diagram with the electrons
to be transferred or shared in the middle
• Draw the bond – Vin diagram
• Determine if the bond is ionic (one reaches 8)
metal bonded to non-metal or covalent (both
reach 8), non-metal bonded with non-metal
• Determine whether a single, double or triple
bond has occurred

44. Steps to Draw Molecular Structures
• Determine the elements
• Determine the atoms
• Determine the number of molecules
• First elements is always the center of the
structure
• Additional elements are drawn around the
center