Unit 5. Chemistry

       Table 4, Period 3

        Riley, Ricky, Nicholas

Description: For Unit 5, we learned about chemistry. Chemistry described in one word is reactions. There are two types of reactions, physical and chemical. A physical change is where an object changes some of it's physical properties but stays the same object. Also if it can change back into it's original object it was a physical change. An example is, melting ice, If you melt ice it turns into water, but you can get it back to ice by freezing it. A chemical change is where an object changes into a completely  different object. An example is, Wood burning because if you burn wood you can't get it back. In chemistry we also learned if an object was a solid, liquid, gas. Another big part of chemistry is atoms. In an atom there are protons, electrons, neutrons. Protons have a positive charge, Electrons have a negative charge , and neutrons have a neutral charge. We learned about isotopes, and different chemicals. There is a chart called the periodic table of elements and it has chemicals on it that give it it's name, symbols, and more. Balancing and combining is also a big part of chemistry. Chemistry is all about reactions and is in our every day lives but we don't always know about it.

Standards Covered:

3. Each of the more than 100 elements of matter has distinct properties and a distinct atomic structure. All forms of matter are composed of one or more of the elements. As a basis for understanding this concept:

1. Students know the structure of the atom and know it is composed of protons, neutrons, and electrons.
2. Students know that compounds are formed by combining two or more different elements and that compounds have properties that are different from their constituent elements.
3. Students know atoms and molecules form solids by building up repeating patterns, such as the crystal structure of NaCl or long-chain polymers.
4. Students know the states of matter (solid, liquid, gas) depend on molecular motion.
5. Students know that in solids the atoms are closely locked in position and can only vibrate; in liquids the atoms and molecules are more loosely connected and can collide with and move past one another; and in gases the atoms and molecules are free to move independently, colliding frequently.
6. Students know how to use the periodic table to identify elements in simple compounds.

5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a basis for understanding this concept:

1. Students know reactant atoms and molecules interact to form products with different chemical properties.
2. Students know the idea of atoms explains the conservation of matter: In chemical reactions the number of atoms stays the same no matter how they are arranged, so their total mass stays the same.
3. Students know chemical reactions usually liberate heat or absorb heat.
4. Students know physical processes include freezing and boiling, in which a material changes form with no chemical reaction.
5. Students know how to determine whether a solution is acidic, basic, or neutral.

6. Principles of chemistry underlie the functioning of biological systems. As a basis for understanding this concept:

1. Students know that carbon, because of its ability to combine in many ways with itself and other elements, has a central role in the chemistry of living organisms.
2. Students know that living organisms are made of molecules consisting largely of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.
3. Students know that living organisms have many different kinds of molecules, including small ones, such as water and salt, and very large ones, such as carbohydrates, fats, proteins, and DNA.

7. The organization of the periodic table is based on the properties of the elements and reflects the structure of atoms. As a basis for understanding this concept:

1. Students know how to identify regions corresponding to metals, nonmetals, and inert gases.
2. Students know each element has a specific number of protons in the nucleus (the atomic number) and each isotope of the element has a different but specific number of neutrons in the nucleus.
3. Students know substances can be classified by their properties, including their melting temperature, density, hardness, and thermal and electrical conductivity.