GOAL 1 - All Living Things are Made Up of Matter
Matter is the Stuff Around You
Matter is everything around you. Matter is the “stuff” that all objects
and substances in the universe are made of. Because all matter
takes up space (has volume) and contains a certain amount of
material (has mass), all matter can be detected and measured.
Matter is anything that has mass and takes up space.
Matter is anything made of atoms and molecules. If you are new to
the idea of mass, it is the amount of stuff in an object.
You can observe some types of matter easily with your senses. For
example, coy can see of feel things like rocks, trees, bicycles, and
animals. And you can see and smell things like smoke from a fire.
Other types of matter are a little more difficult to observe. The dust mites that live in your bed and rugs
are an example of matter that is too small to see with the naked eye. They can be observed only with
special instruments like a microscope. Another example of matter that’s hard to detect is air. How do
we know it is there? You can’t see it but you know it exists because you can feel (and sometimes smell
it) it when the wind blows and see it bend the branches of trees.
The word matter comes from the Latin word materia meaning “material” or “stuff”.
Matter is Made Up of Atoms
Imagine finding a gold nugget while panning for gold. You decide to share your prize with family and
friends by having it cut into smaller pieces. Using a special tool, you cut the nugget in half, then in half
again, over and over. Eventually you end up with a piece of gold that is too small to cut with your tool!
But you have a lot of family and friends, so suppose you were able to keep cutting the gold into smaller
and smaller pieces. Would you be able to keep cutting forever? No! At some point you would end up
with a piece that could not be divided. That smallest piece would be an atom.
An atom is the smallest particle into which an element (such as gold) can be divided and still maintain
the properties of that element (it would still behave and look like gold). Because all matter is made up
of elements, and all elements are made up of atoms, atoms are considered the building blocks of
matter.
You are made up of matter and that matter is made up of billions and billions of atoms. The word atom
comes from the Greek word atomos, which means “indivisible” or “uncuttable”.
GOAL 2 – Atoms are Made Up of Protons, Neutrons, Electrons
Atomic Structure (What they are made of)
Atoms are made up of even smaller particles. Even though super-tiny atomic particles exist, you only
need to remember the three basic parts of an atom: electrons, protons, and neutrons. Protons and
neutrons stick together to form an atom’s nucleus, which is at the center of the atom. Electrons are
found in regions surrounding the nucleus.
Protons are positively charged particles located in the nucleus of an atom. All protons are identical.
An atom is identified by the number of protons in its nucleus. The number of protons an atom has is
identified by its atomic number. For example, an atom with one proton is called hydrogen and has an
atomic number of 1. An atom with eight protons is called oxygen and has an atomic number of 8. All
atoms of the same element have the same number of protons.
Neutrons are also located in the nucleus. As their name
suggests, neutrons are electrically neutral. That is, they have no
electric charge. All neutrons are identical. Sometimes, atoms of
the same elements have different numbers of neutrons. Because
neutrons have not charge, the overall charge of the atom is not
changed by the extra neutrons.
Electrons are the negatively charged particles found outside the
nucleus of an atom. All electrons are identical. The number and
arrangement of the electrons in an atom determine its chemical properties (how it will behave as a
chemical).
The nucleus of hydrogen, the simplest atom, contains one proton but no neutron. All other atoms have
both protons and neutrons in the nucleus.
Scientists used to think that electrons orbited the nucleus the way planets orbit the sun. Now they think
that electrons travel in random paths in an area around the nucleus called electron clouds. An
electron’s energy level determines its average distance from the nucleus. The charge of an electron is
equal to the charge of a proton, but opposite in sign.
Atomic Size
Just how small is an atom? There are more than a million million billion atoms in a single drop of
water! The protons and neutrons that make up the nucleus of an atom have about the same mass.
Electrons have a much smaller mass-about one two-thousandth the mass of protons or neutrons.
That means most of the mass of an atom is in the nucleus. The particles that make up an atom are
like tiny specks compared to the size of the atom as a whole. So the majority of an atom’s volume
consists of empty space.
BE PREPARED TO DRAW ANY ATOM. Remember the atomic # tells you the number of protons
the atom has and that tells you the # of electrons it has. The # of neutrons = Mass – # Protons./
GOAL 3 – Elements are Organized on the
Periodic Table of Elements
Matter
All matter is made up of atoms. But think about all the different kinds of matter there are in the
universe. What makes one kind of matter different from another? Different kinds of atoms! Different
kinds of atoms are called elements. Each element is a little bit different from the rest.
You are made up of billions and billions of atoms. However, you may only find about 40 elements
inside of your body. You would find hydrogen (H) atoms, oxygen (O) atoms, and a bunch of others.
Those other atoms are made of the same basic pieces, but they are organized in different ways to
make each element unique.
Periodic Table of Elements
Back in 1869, Russian chemist Dmitri Mendeleev organized all the know elements into a chart
according to their properties. Today the chart is known as the periodic table of elements.
The periodic table is made up of horizontal rows and vertical columns of boxes. Each box contains
specific information about a single element. This information includes the element’s name, the
chemical symbol for the element, the element’s atomic number, and the element’s atomic mass.
The chemical symbol is one or two letters used to represent the element’s name. Many of the
chemical symbols used in the periodic table come from the Latin words for those elements. For
example, Fe is the symbol for the element iron. The Latin word for iron is ferrum.
The atomic mass is the average mass (like weight) of an atom of that element. Atomic mass is
measured in atomic mass units (amu). The atomic mass can be found by adding the number of
protons and neutrons in that atom’s nucleus. Electrons do not add to the mass because they are so
small.
The atomic number is the number of protons in an atom of that element.
Each row of elements in the periodic table is called a period. If you read the elements in each period
from left to right, you will see that they are arranged in order by their atomic number.
So as you move along the periodic table from left to right the atoms gain one proton in their nucleus
with each new element.
There are almost 120 known types of atoms, only 92 are found naturally on Earth or in the
atmosphere, the rest were made in a lab. That means there are almost 120 elements on the periodic
table of elements. Everything in the universe is made up of the elements on the periodic
table of elements.
GOAL 4 – Atom, Element, Molecule, Compound, Mixture
Elements
All matter is made up of atoms. But think about all the different kinds of matter there are in the
universe. What makes one kind of matter different from another? Different kinds of atoms! Different
kinds of atoms are called elements. Each element is a little bit different from the rest.
There are almost 120 known types of atoms, only 92 are found naturally on Earth or in the
atmosphere. That means there are almost 120 elements on the periodic table of elements.
Everything in the universe is made up of the elements on the periodic table of
elements.
The Earth’s crust is made up mostly of the elements oxygen and silicon. Earth’s atmosphere is about
78% nitrogen and 21% oxygen. Living things are made mostly out of combinations of the elements
carbon, hydrogen, oxygen and nitrogen (CHO).
Each element is made of atoms of the same type. For example, the element oxygen is made out of
oxygen atoms. The element carbon is made out of carbon atoms. Each element is considered a
pure substance because it contains only one kind of atom.
Two or more elements that have combined (bonded) are called a compound.
Compounds
Two or more elements that have combined (bonded) are called a compound. Most elements are
found in combinations with other elements-that is, in chemical compounds. The elements in any
given compound have a fixed ration. For example, the compound water (H 2O) always has two parts
of the element hydrogen to one part of the element oxygen.
The properties of compounds are different from the properties of elements that make up the
compounds. For example, water has properties that are different from either hydrogen or oxygen, the
elements that make up water.
Sugar is a compound made up of C12H22O11 or 12 Carbon atoms, 22 Hydrogen atoms, and 11
Oxygen atoms that have bonded and are repeated in the same ratio over and over again.
Molecules
The smallest particle of a compound is called a molecule. Many sugar molecules make up the
compound sugar.
When two or more atoms combine they form a molecule. Just as an atom is the smallest particle of
an element, a molecule is the smallest particle of a compound.
The simplest molecules contain only two atoms. For example, an oxygen molecule (O 2) is made up
of two oxygen atoms (O) that have joined together. A hydrogen molecule (H 2) consists of two
hydrogen atoms (H).
Most molecules are made out of two or more atoms of different kinds (different elements). For
example, a water molecule (H2O) is made of two hydrogen atoms (H) and one oxygen atoms (O).
Each molecule of water behaves like water. If the molecules are divided into separate hydrogen and
oxygen atoms, however, the particles no longer behave like water.
Compounds are groups of two or more elements that are bonded together. You have also seen the
word molecule to describe atoms that are bonded together. Every combination of atoms is a
molecule. Compounds happen when atoms from different elements bond into molecules that are
repeated regularly. So, all compounds are made up of molecules, because they have bonds between
the atoms, like in water (H2O). However, not all molecules are compounds because sometimes the
atoms are of the same element.
Mixtures
As you might guess, mixtures are just the way we describe a mixture of atoms, elements, molecules,
and compounds. The atoms, elements, molecules, and compounds that are found in mixtures have
not bonded to one another so they can be separated from one another without causing a chemical
reaction to occur.
Tap water is a mixture of atoms and molecules and
distilled water is a compound because it is made up
two elements that are repeated in the same pattern
(H2O) over and over again.
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