Review

Review

  • Submitted By: yagout
  • Date Submitted: 10/05/2008 2:01 AM
  • Category: Science
  • Words: 443
  • Page: 2
  • Views: 337

1. What is the definition of matter? It is the material substance of the universe that has
mass, occupies space, and is convertible to energy

2. What is the difference between an atom, element, molecule and compound?

Atom: the smallest portion into which an element can be divided and still retain its properties, made up of a dense, positively charged nucleus surrounded by a system of electrons. Atoms usually do not divide in chemical reactions except for some removal, transfer, or exchange of specific electrons.

Element: any of the four primary substances, earth, air, fire, and water, that were formerly thought to be the materials from which all matter is constructed

Molecule: the smallest physical unit of a substance that can exist independently, consisting of one or more atoms held together by chemical forces

Compound: chemistry a substance formed by the chemical combination of elements in fixed proportions

3. What 2 things does every element have so that it makes it easy for communication with others anywhere in the world? Atoms, molecule, & compounds.
4.What are the rules when writing element symbols? Element symbols are either one or two letters. If the symbol is one letter, capitalize it. If the symbol is two letters, capitalize the first and the second is lower case.
5. Find the names and chemical formulate for 5 compounds that we have not studied in class. List how many atoms there are in total as well as how many of each element just like we did in class.
Compound Total # of atoms
NaCl 2 (table salt)
CO2 3(Carbon Dioxide)
HCl 3(Hydrochloric Acid used in your stomach to break down food.)
O2 2(Oxygen)
C12H22O11 45(table sugar)

6. Explain the definition of mixture.
A substance containing several ingredients mixed together, such as a cake mixture.

7. How is a mixture different from a pure substance?
A Pure substance is natural & a mixture is made up of 2 things or more.
8. Explain the difference...

Similar Essays