Unit 5-Chemistry

Table 6 Period 7

Maddie M

Zac R

Anthony H

In this unit we covered atoms, molecules, the periodic table of elements, the law of conservation mass, changes of state, chemical and physical changes, and the pH scale. An atom consists of protons, electrons, and neutrons. Protons and neutrons are located in the nucleus, and the electrons are located outside the atom. The periodic table of elements provides the list of all the elements, their protons, neutrons, electrons, and atomic mass. The law of conservation mass states how mass can not be created or destroyed. There are three states, solid (molecules vibrate), liquid (molecules slide) and gas (molecules bounce around). The difference between a chemical and a physical change is that a chemical change can not be undone, and a physical change can.  Some examples of a physical change are chopping, melting, freezing, and molding. These are all changes that can be undone. However chemical changes, such as fizzing, changes in color or temperature, can no be undone. A chemical change creates a whole new product..The pH scale is used to determine wheather a liquid is a neutral, an acid or a base. The pH scale ranges from 0-14. Any liquid that is 0-6.9 is an acid, the lower the number is, the stronger the acid is. Acids eat away at tissues very quickly, battery acid is a form of an acid, however orange juice is also an acid, but is not nearly as strong as battery acid. 7 is neutral, water is an example of a liquid with a neutral pH. 7.1-14 are bases. Thne higher the number the stronger the base,. Bases, like acids eat away at tissue, however much slower than acids. Milk is a common base, however won't eat away a tissue because it is not a strong base. In this chemistr unit we hd tons of fun learning how to build an atom, read a periodic table, and conduct experiments and understand the results. Yeah!

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.