This document introduces physical science and provides an overview of matter. It discusses that matter is anything that has mass and takes up space, and is made up of atoms. Atoms contain protons, neutrons, and electrons. Protons and neutrons are located in the central nucleus, while electrons orbit around the outside. Multiple atoms can be joined together to form molecules. Elements are pure substances made of only one type of atom, while compounds are made of two or more different elements combined together. Mixtures contain a combination of different substances that can be separated out, whereas solutions are homogeneous mixtures where one or more substances are uniformly distributed throughout another substance.
3. Matter - What is it?
...and what is it NOT?
• Matter is anything that:
• has mass
• takes up space
• All matter is made up of atoms
• more than 100 different kinds
4. Experiment 1.1
Density: mass and volume
• Which of these rods has the
greatest mass?
• Write down your hypothesis
• Observation:
• What do you know?
• What do you want to
know more about?
• Hypothesis:
• What do you think will
happen (& why)?
• Experiment:
• Record the data
• What happened?
• Conclusion:
• Was your hypothesis
correct?
• What's next?
5. • Atoms are the smallest unit of particles comprising matter
• every atom is made up of
• at least one positively charged proton
• one or more neutrons (except hydrogen)
• one or more shells of negatively charged electrons
• Most of what makes up an atom
is EMPTY SPACE!!!
What is matter made of?
in a dense, central nucleus
Atoms are mostly empty space!
6. Nuclear Particles
• Protons
• located in the nucleus of an atom
• each proton has a positive (+1)
charge
• "heavy" (has a significant mass)
• The number of protons in an
atom determines the type of
element
• 1 proton = Hydrogen
• 3 protons = Lithium
• 8 protons = Oxygen
• # of protons can be found on
the periodic chart as the atomic
number
p+
7. Nuclear Particles
• Neutrons
• located in the nucleus
• neutrons have no charge (0)
• "heavy" (has a significant mass)
n0
• The number of neutrons varies
within elements
• # of neutrons can be determined
using the periodic chart
• atomic mass = average weight of
protons & neutrons combined (taking
into account all its isotopes)
• neutrons = atomic mass (rounded to
nearest whole #) minus the atomic
number
8. Orbiting Particlese-
• The number of electrons
usually equals the number of
protons (atomic #)
• When the # of negative
charges (electrons) equals # of
positive charges (protons), they
balance out.
• Sometimes there are extra or
missing electrons.
• This results in an ion (net (-) or
(+) charge on the atom)
• Electrons
• zip around outside the nucleus
• impossible to know the exact position or velocity
• each electron has a negative (-1) charge
• "light" (contributes virtually nothing to the mass
of an atom)
9. Atoms vs. Molecules
• Compounds are pure substances made from a
single type of molecule (two or more different
combined elements)
• ratios remain constant (there will always be twice
as much Hydrogen as Oxygen in water)
• i.e. carbon dioxide, sodium chloride (salt), iron
oxide (rust), ammonia (NH3), water, chalk (CaCH3)
• Two or more atoms joined
together make a molecule
• can be same or different kind
of atom
• different properties than the
individual atoms that form it
Oxygen Molecule O2
Water Molecule H2OOxygen atom O
• Elements are pure substances made from only one type of atom
• i.e. gold, carbon, helium, neon, sulfur
• all listed in the Periodic Table of the Elements
10. Mixtures
- What examples can you think of?
• A mixture is made of different substances (two or more
compounds) that can be physically separated
• Separate substances mix, but keep their individual characteristics
• contain different ratios of substances
• examples:
• some fruit salad might have more grapes than bananas
• some granite has more feldspar in with the mica than others
Granite
• How can substances be separated out of
mixtures?
• by hand or with tweezers
• evaporation or distillation
• filtering
• settling in layers (centrifuge)
• magnets
11. Mixtures -
Fruit Salad vs. Whipped Cream
• Heterogeneous mixtures are unevenly mixed
• different substances clump together
• easily identified as separate substances
• examples: granite, soil, sand, salad dressing, OJ
• Homogeneous mixtures are evenly mixed
• particles are uniformly dispersed (spread out)
• even with a microscope, different substances
can't be identified
• examples: air, brass, antifreeze, whipped
cream, apple juice
Advanced
Topic
**Ask yourself, “Will two different scoops
have the exact same ratio of ingredients?”
12. Solutions
• A solution is a homogeneous mixture in which one or more solutes (particles
of a substance) are distributed uniformly throughout another substance (the
solvent)
• solutes & solvents can be solids, liquids or gases
• But both parts (solute and solvent) must be in the same state of matter
• the solvent is the substance in greatest quantity in the solution
• Examples:
• air is a solution of several different
gases (O2, CO2, Ar) equally distributed in
Nitrogen gas
• alloys (such as sterling silver or dental
fillings) are solid solutions
• carbonated drinks are sugar, flavorings
and carbon dioxide gas solutes
uniformly dispersed in water
Advanced
Topic
White Board: draw an atom! Or WHAT IS MATTER?
(to assess familiarity with atomic structure)
Opening Activity: decorate LAB NOTEBOOKS and label with name.
What makes something like a bike (hard, cool, metalic, smooth) different than a tree (rough, flamable, fibrous)? The atoms that make up each object have different properties.
Things that cannot be physically described or measured are usually NOT comprised of matter (kindness, God, hunger, ideas). In scientific terms, things like sound waves and light contain a certain amount of energy, but not mass and therefore are not comprised of matter. Dark matter is a concept in theoretical physics of something that has mass but no volume.
Experiment vs. Demonstration discussion: https://sciencebob.com/category/science-fair-ideas/
Density bars, scale, lab notebooks
optional: graduated cylinders & water
- explain difference between volume, mass, and density
- focus on mass and discuss the scientific method
Each material is made up of different atoms, held together in different combinations
Rods include:
brass, a homogeneous mixture (and solution) of primarily copper (67%) and zinc (33%)
aluminum, a metal element
nylon, a plastic polymer (very long, repeating molecules)
PVC (poly vinyl chloride), another polymer made from chlorine and petroleum products
clear acrylic, yet another plastic polymer from which Plexiglas is made (also from petroleum)
This can be confusing, because in everyday language, when we ask, "how much does that weight?" we are REALLY (in scientific terms) asking what its mass it.
Quick review on rounding to a whole number:
Jeanne's method:
circle the one's place number
draw arrow to number on the right
if it's 5 or above, the circled number is raised one digit
if it's 4 or below, the circled number STAYS THE SAME
In the example here, round the mass to 96. Neutrons = 96-42 = 54
Isotopes: One of two or more atoms that have the same atomic number (the same number of protons) but a different number of neutrons. Carbon 12, the most common form of carbon, has six protons and six neutrons, whereas carbon 14 has six protons and eight neutrons. Isotopes of a given element typically behave alike chemically. With the exception of hydrogen, elements found on Earth generally have the same number of protons and neutrons; heavier and lighter isotopes (with more or fewer neutrons) are often unstable and undergo radioactive decay .
Elephant vs. mouse in weight to compare proton/neutron to electron.
Don't go into too much detail at this point about valence electrons and reactivity.
chalk = calcium carbonite (CaCH3)
ammonia = NH3
Jell-O is a colloid: a heterogeneous mixture with particles larger than those in a solution, but not large enough to settle out. Milk, paint, and mayo are, too (and aerosols).
Water can be chemically separated into oxygen and hydrogen but is not a mixture because those elements cannot be physically separated.
Materials: salt, ferro-fluid, sand, beaker and water source
brass = copper + zinc
vinegar = acetic acid and water
In a salt solution, Na and Cl dissociates into ions in order to form a homogenous mixture.
CuSO4 = copper sulfate
Challenge students to find a pure element and bring it to class next week.
Cast iron skillet has ~2% carbon.
Graphite pencil is carbon + clay.
Silver or gold jewelery usually has quite a bit of other metals thrown in to make it stronger (less soft/malleable).
Lead bullets or fishing weights have less than 5% other metals.
A helium balloon, magnesium fire starter, copper pipes/fittings, diamond ring, aluminum foil, argon and tungsten in light bulbs.
Materials: salt (kosher or rock salt along with table salt), black construction paper squares, hand lenses, microscope, ferro-fluid
Sand