Chemistry

Why is speaking highly of yourself important?

March 15 Bell Work

Open Ended

What is the smallest basic unit of matter?

Multiple Choice

A substance made of only one type of atom that can not be broken down by chemical means

• Compound

• Element

• Molecule

• Atom

Multiple Choice

a bond where electrons are shared between two atoms

• Ionic

• Covalent

• Hydrogen

• Chemical Reaction

​Atoms and Elements

• Every physical thing you can think of, living or not, is made up of small particles called atoms

  • Atoms are the smallest most basic unit of matter

• Atoms structure can be depicted several different ways

• Trillions of atoms can exist in just one dot on your paper

• An element is a substance made up of one type of atom that can not be broken into simpler substances by ordinary chemical means

Atomic Structure

• Atoms are composed of three smaller particles

  • Electrons (-)

  • Protons (+)

  • Neutrons (neutral)

• Protons and neutrons can be found at the center called the nucleus

• Electrons are surrounding the nucleus

  • Electrons have been depicted in rings or a cloud

Open Ended

What is an example of an element?

​Elements & Periodic Table

• All the atoms of a given element have a specific number of protons

  • Oxygen has 8 protons

• This number will never change

• Each atom has a different amount of protons

• Because proton number never varies, we use the number of protons to identify each element, also known as the atomic number

  • Oxygens atomic number is8

Open Ended

What is the atomic number for Carbon (C)?

Draw

Draw a four leaf clover under a rainbow

​Atomic Number

• The atomic number can be also be found on the periodic table for each element

• The atomic mass is the total mass of the element

  • Electrons almost account for no mass at all

  • The atomic mass is approximately the sum of the protons and neutrons

• Oxygen has 8 protons and a atomic mass of 16

  • 16-8= 8 neutrons

​What is an eclipse?

• Sometimes when the Moon orbits Earth, the Moon moves between the Sun and Earth. When this happens, the Moon blocks the light of the Sun from reaching Earth

• Total solar eclipses are particularly important because they allow scientists to see a part of the Sun’s atmosphere – known as the corona – that’s too faint to see except when the bright light of the Sun is blocked

• Everywhere will not experience the full eclipse, some places will only have a partial, and other parts of the world will see none at all

​Why is looking at the eclipse dangerous?

• The sun's bright rays can burn cells in the retina at the back of the eye

• The retina doesn’t have pain receptors, so there’s no way to feel the damage as it happens

• Once the cells die, they don’t come back

• Symptoms of solar eye damage, called solar retinopathy, include blurred vision and color distortion

​Modeling Chemical Reactions

• To understand chemical reactions, we need to know the inputs and outputs

• Reactants are the initial substances in the chemical reaction

• As the reaction takes place the bonds of the reactants are broken and rearranged to form the products of the reaction

• The products of a reaction are different from the reactants, all the same atoms are present, but their rearrangement produces new substances

Open Ended

The reactants are on which side of the chemical equation

​Modeling Chemical Reactions

• Chemical equations model what happens in a chemical reaction

• In a chemical equation, the reactants are on the left side of the equation and the products are on the right

• Chemical reactions model the conservation of matter

  • This means that in chemical reactions, atoms are not created or destroyed, only rearranged

• All the atoms from the reactants will be present in the products once the reaction is complete

Open Ended

How do you know if a chemical equation is balanced or unbalanced?

Draw

Draw the moon and sun as best friends

​Chemical Equilibrium

• Some chemical equations go from reactants to products until all of the reactants are consumed

• This reaction can only proceed in one direction and is irreversible

• These type of reactions will have an arrow pointing toward the product

​Chemical Equilibrium

• Some chemical reactions are like a two way street

• They are reversible

• Arrows pointing in both directions signify a reversible chemical reaction

• These reactions will occur until they reach and equilibrium point

• This means the reaction reaches a point where the reaction occurs in both directions at an equal rate

​Solid

• A solid is one of the three basic states of matter

• A solid is that state of matter which has a fixed shape, mass, and volume

• A solid forms from liquid or gas because the energy of atoms decreases when the atoms take up a relatively ordered, three-dimensional structure

• All solids have, for example, the ability to resist forces applied either perpendicular or parallel to a surface

Open Ended

Can we change objects from solid to liquid, and liquid to gas? How?

​Liquid

• Liquid is one of the three states of matter, intermediate between gas and solid

• The most obvious physical properties of a liquid are its retention of volume and its conformation to the shape of its container

• When a liquid substance is poured into a vessel, it takes the shape of the vessel, and, as long as the substance stays in the liquid state, it will remain inside the vessel

• the molecules in a liquid are free to move about, but there is some order because they remain relatively close to one another

​Gas

• Gas, one of the three fundamental states of matter, with distinctly different properties from the liquid and solid states.

• The remarkable feature of gases is that they appear to have no structure at all.

• They have neither a definite size nor shape

• Gases will completely fill any closed container

Draw

Draw a warm spring day

​Changing States of Matter

• All matter can move from one state to another.

• It may require extreme temperatures or extreme pressures, but it can be done

• Phase changes happen when you reach certain special points.

• Sometimes a liquid wants to become a solid.

  • Scientists use something called a freezing point or melting point to measure the temperature at which a liquid turns into a solid