Download Magnet Background Knowledge

Content Knowledge- Magnets Second Grade
Magnets are made of metal and can be many shapes, sizes and strengths. Magnets are the
strongest at their poles and are classified as objects that have a magnetic field around them which attracts
or repels certain materials. Magnets have two poles, a north pole and a south pole. Magnets attract to each
other when the north pole of one magnet sticks to the south pole of another magnet. Magnets repel from
one another when two of the same poles are facing each other. If the north pole of one magnet is facing
the north pole of another magnet they will push away, this is an example of magnets repelling.
Magnets are made of metals containing iron, cobalt, nickel, or steel, once those materials are
exposed to a magnetic field they become a magnet. Metals such as copper, silver, magnesium, and
aluminum are metals that are not attracted to magnets. The magnetic field of a magnet rearranges the
metals molecules in a north and south pattern turning them into magnets. A magnetic field is an invisible
area around the magnet where it can attract or repel things. A magnet will affect a magnetic object only
when it enters its magnetic field. The strength of a magnet is stronger as you get closer to it and its
strength weakens as you get farther from it (“BrainPop”, 2014).
Magnets come in different shapes, sizes and strengths and can be used for a variety of things.
There are both natural magnets and man made magnets. Natural magnets are found in the form of rocks,
one natural magnet is a rock called a lodestone. Natural magnets are called magnetite, and are rich in iron
and minerals. Man made magnets come in a variety of shapes, such as horseshoe, block, rod, bar, and
horseshoe. Magnets are used in toys, appliances, and hundreds of house hold things, they are also used in
industries and manufacturing plants. (“HubPages”, 2014).
There are three types of man made magnets; permanent magnets, temporary magnets, and
electromagnets. Permanent magnets are very strong and are the most commonly used magnet. Permanent
magnets are magnets that do not lose their magnetic field. They are objects made from a material that is
magnetized and creates its own persistent magnetic field. The most common example of a permanent
magnet is a stick on refrigerator magnet.
Temporary magnets are those magnets which act as magnets only when placed in a strong
magnetic field provided by a strong magnet. Examples of temporary magnets are metallic objects such as
paper clips and nails that when placed in a strong magnetic field can act as magnets. Once those materials
are removed from the field, they instantly lose their magnetism. Paper clips, nails and pins act like
magnets when a magnet is brought near them because the magnet makes the atoms in iron materials line
up.
An electromagnet is a magnet that runs on electricity. It consists of a heavy metal core which is
wounded my a wire coil. When a current is passed through the wire it produces a magnetic field,
magnetizing the metal core. Unlike permanent magnets, the strength of an electromagnet can be changed
by changing the amount of electric current that flows through it. The poles of an electromagnet can also
be reversed by reversing the flow of electricity. Electromagnets are most commonly used in televisions,
radios, and computers (HubPages, 2014).
The earth itself is a large magnet with a large magnetic field. The earths core is largely made up
of iron, the other portion of the core is liquid iron that spins and makes the earth into a giant magnet. The
earths north and south poles are positive and negative which makes the earth a giant magnet. Because of
this we can use magnets in compasses to navigate our way around. The earths magnetic field protects us
from the suns solar winds and radiation (“Physics for Kids”, 2014).
Bibliography
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Content Knowledge- Trees Kindergarten
The science topic my classroom is working on at this time is trees, for my lessons I will be
focusing on leaves. The children have been learning about the seasons and how a trees appearance
changes from season to season. With it being fall the children have been learning how apples grow, the
colors leaves are in the fall, and how trees have green leaves in the spring and summer then turn to red,
orange, yellow, and brown in the fall and eventually fall from the tree leaving it brown and bare in the
winter.
My lessons will be focusing on why leaves change color, how they can be different shapes and
sizes, the parts of both a leaf and tree, and how leaves change through the process of photosynthesis. The
parts of the tree include the roots where the water is soaked up through the ground, and then travels
through up the trunk to the branches and eventually to the leaf. The stem of the leaf is what is attached to
the branch. The stem is connected to the veins of the leaf where the water disperses to the blade of the
leaf, this is where the majority of the color can be seen and where the sunlight and air (carbon dioxide) is
soaked up and photosynthesis occurs.
There are many types of trees, with that there are many different kinds of leaves with different
shapes and sizes, Maple leaves look different than Oak leaves, and Elm leaves. During the fall the leaves
change color due to less sunlight and heat. These changes effect the amount of food the tree makes, this
food is a type of sugar that gives the leaves its green pigment. Chlorophyll is what makes the leaf green,
whiteout this the tree wouldn't be able to use sunlight to produce food.
Tree’s, unlike humans, make their own food, the ingredients for their food are sunlight, air
(carbon dioxide) and water. In the summertime the air is warm and there is many more hours of sunlight
which allows the leaves to stay green due to the amount of food they are able to make, and the amount of
water the tree sucks up from the ground. When the fall comes there is less sunlight, and less heat, the tree
realizes that winter is approaching so it stops sending water to the leaves. When the leaves stop getting
water they are unable to make their own food and the green chlorophyll starts to disappear.
As the tree prepares for winter and the leaves get less water the stem starts to detach from the
branch of the tree and falls to the ground. The fall colors/pigments you see are made from the sugar the
leaves have stored up, and can be seen when the leaves start to die. When the leaves start to die the green
color goes away because the leaf is not making any new food, it is using the food it has stored up over the
summer. This stored sugar in the leaf causes it to turn from green to red, orange, and yellow. When the
leaf has no more stored sugar it loses all of its color and turns brown. As the leaves separate from the tree
they fall to the ground leaving the tree brown and bare for winter.