Lessons 6,9, and 10

Lesson 6 - A New Language

Chemical Names and Symbols

All matter in the universe is and element or a combination of elements.

Element - a unique substance that cannot be broken down into simpler substances through any chemical process. ex: Na or Sodium is an element on the periodic table.

Compound - a pure substance that is a chemical combination of two or morelements in a fixed ratio. ex: H2O is water and since H2O is a compound then this means that water is made up of 2 Hydrogen atoms and 1 oxygen atom.

• Compound are represented by chemical formulas. 

Chemical Formula - combination of symbols and subscripts that indicates the number and types of elements in a compound.

• Substances come in different physical forms called phases.

Phase - physical form a substance is in like solid, liquid, or gas.

Aqueous - when a substance is dissolved in water.

Practice Problems
3) How many elements are included in the chemical formula for sodium nitrate, NaNO3? Name them.
Three elements; sodium,Na, nitrogen, N, and 3 oxygen atoms, O3. 
4) What is the difference between NaOH(s) and NaOH(aq)? The s after the compound indicates that it's physical form is solid while aq indicates liquid. 

Lesson 9 - Create a Table

Properties of the Elements

Atomic Mass - the mass of a single atom (or isotope) of an element.

Reactivity - property describing whether an element or compound will chemically combine with other substances as well as the speed of the reaction.

• The periodic table is organized based on the properties of elements with columns of elements on the table share similar properties, reactivity, and atomic mass.

Practices Problems

2) Do you expect carbon,C, to be more similar to nitrogen, N, oxygen, O, or silicon,Si? Why?

Carbon should be more similar to silicon because they are in the same group and elements in the same group share properties. 

5) Suppose you have equal amounts of calcium, Ca, in two beakers. You react the calcium in one beaker with oxygen, O, and the other with sulfur, S. The reaction between calcium and oxygen forms compound CaO. 

1. What do you predict is the chemical formula of the compound formed from the reaction between calcium and sulfur? CaS
2. Which compound has more mass? Explain? The calcium and sulfur compound because their combined mass is 36 not 28. 

Lesson 10 - Breaking the Code

The Periodic Table

Atomic number - the atomic number of an element is the same as the number of protons in the atom of that element. Can be identified as the whole number associated with the element on the periodic table.

Group - a vertical column in the periodic table elements in the group sharing similar properties

Period - Horizontal rows on the periodic table.

Metals - elements that are excelled conductors of heat and electricity, shiny and malleable

Nonmetals - elements that are poor conductors of heat and electricity, dull and brittle, and found to the right of the stair-step line.

Metalloids - elements between the metals and nonmetals,

Practice Problems
5) Which of these elements are solids? B-Titanium,Ti  C-Lead, Pb  E-Poyassium, K  F-Silicon,Si.
6) Which of these elements are nonmetals? A-Bromine, Br  B-Carbon, C  E-Phosphorus, P

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