Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Do you really want to delete this prezi?
Neither you, nor the coeditors you shared it with will be able to recover it again.
Make your likes visible on Facebook?
Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.
Changes in Matter - KGIC
Transcript of Changes in Matter - KGIC
Changes in Matter Review: Atoms and Molecules Changes in Matter:
Chemical Physical change - a change in the form of matter that does not make a new substance Atom - basic unit of matter; what matter is made of Molecule - a tiny unit of matter formed when atoms combine Combine - join together to make one Break/snap Rip/tear Melt Change in state = physical change Review: Changes in State Evaporate - to change from a liquid to a gas Condense - to change from a gas to a liquid Freeze - to change from a liquid to a solid Melt - to change from a solid to a liquid Form - the shape or structure of a substance Substance - something that has matter; something that has mass and takes up space Chemical Change - a change in matter that makes a new substance Physical and Chemical Changes
Worksheets Review: Parts of an Atom Solid Liquid Gas Burn / Combust - to change a substance using fire or heat Cook - to prepare food (changing the molecules) using fire or heat Prepare - to get ready Rust - when oxygen combines with iron to form a brown substance called "rust" (iron oxide) Corrode - to eat or wear away a substance by a chemical change State - what something is at a particular time (ex. solid, liquid, gas) Atoms have electron shells or energy levels. These are groupings or layers of electrons. Each shell can only have a maximum number of electrons. Maximum - the most or highest something can be The first shell (called "K"), can have a maximum of 2 electrons. When the outer shell is full, the atom is stable. Stable - not likely to change or react. For the first 20 elements, the maximum electrons in each shell, moving outwards, is 2, 8, 8, 2. A potassium atom looks like this: After that, the maximum electrons in each shell, moving outwards, is 2, 8, 18, 18, 32, etc. A gold atom looks like this: This helps us organize the Periodic Table: Remember: an element's atomic number is how many protons it has. Most elements will have a neutral charge, or the same number of protons (+) and electrons (-). +3 and -3 = 0 (neutral charge) The electrons in an element's outer shell are called valence electrons. Using the shell diagram, how many valence electrons does the element Carbon (C6) have? Worksheet: Valence Electrons Helium:
2 electrons Carbon has 4 valence electrons. Chemical Bonds - How atoms form molecules Most atoms want to be stable. Remember: an atom with a full outer shell of electrons is stable. Valence electrons can bond together with other atoms to form bonds. Bond - when two things join together When atoms share their electrons they form a chemical bond. This is how molecules are formed. A water molecule has two atoms of hydrogen and one atom of oxygen. It looks like this: H Worksheet: Chemical Bonds H is a chemical formula. This is a set of symbols used to show how many atoms are in a molecule. H = 2 hydrogen atoms
O = 1 oxygen atom What do you think the following formula means? CO CO
C = 1 atom of carbon
O = 2 atoms of oxygen 2 O 2 O 2 2 2 2 Chemical Reactions Remember! Some atoms have a neutral charge. This means there is __________________ number of protons and electrons. But...some atoms have _____________________
number of protons and electrons. These atoms are called ions. They have either a positive (+) or a negative (-) charge. Ion - an atom or molecule where the number of protons and electrons are different Positive charge (+) - when an atom or molecule has more protons than electrons. These ions are called cations. Negative charge (-) - when an atom or molecule has more electrons than protons. These ions are called anions. Remember! Atoms want to become stable. This means they have a full outer shell of electrons. Let's look at a neutral atom of oxygen:
It needs 2 more electrons (-) to become stable. Chemical reaction - the process of chemical change; when a change occurs and a new substance is formed Process - a number of actions happening one after another An oxygen ion, with a full outer shell, has gained 2 electrons. This means is has a negative charge of two (2-). A compound is a substance that is made from two or more elements.
Remember carbon dioxide (CO2)? Carbon dioxide is a compound. It is made from carbon and oxygen. What about sodium (Na)? A neutral atom of sodium has 11 protons and 1 valence electron:
When is loses its valence electron, it becomes an ion with a positive charge of one (1+). Sometimes ions can be made of more than one element. Some common ions with more than one element are below:
Ammonium: NH +
Nitrate: NO -
Carbonate: CO 2-
Cyanide: CN - There are two kinds of compounds: ionic compounds and covalent compounds. Ionic compounds - compounds made of metals and non-metals. They are formed when ions gain or lose electrons. Then the ions attract one another to form bonds. Let's go back for a minute...
There are two types of elements: metals and non-metals Metals - elements that are formed easily, conduct heat, and are often shiny Non-metals - elements that are not shiny and are poor conductors of heat. These elements are often gas, but not always. Conduct - to carry or guide Covalent compounds - compounds made of non-metals. They are formed when atoms share their valence electrons. Attract - to pull toward or near Periodic Table Worksheet - Ions Worksheet - Metals and Non-Metals 3 3 4