Question

use pages 106 - 121 to find the answers to fill in the blanks: 4.1 the elements 1. all of the materials in the universe can be chemically broken down into about different elements. 2. compounds are made by combining of the elements just as words are constructed from the letters in the alphabet. 3. nine elements account for about of earths crust, oceans, and atmosphere. use table 4.1 to list the 9 elements: , , , , , , , , and . 4. the elements in living matter are very from those in earths crust. 5. in the human body, oxygen, carbon, hydrogen, and nitrogen are the most elements. 6. top ten elements in the human body are: , , , , , , , , , . 7. each element has a and a . 8. the symbol usually consists of the first one or two letters of the elements name. examples: oxygen , krypton . 9. sometimes the symbol is taken from the elements original latin or greek name. examples: gold au from the latin and lead pb from the latin . 4.2 atoms and compounds 10. law of constant composition: a given compound always has the same by mass of the of which it is composed. 11. daltons atomic theory states: all elements are composed of . all atoms of a given element are . atoms of different elements are . compounds consist of the atoms of elements. atoms are created or destroyed in a chemical reaction. 12. formulas of compounds a compound is represented by a chemical formula in which the and of atoms present is shown by using the element symbols and subscripts. example: the simple sugar, glucose c6h12o6 means there a 6 carbon atoms, hydrogen atoms and 6 oxygen atom. 13. rules for writing formulas a. each atom present is represented by its element . b. the number of each type of atom is indicated by a written to the right of the element . c. when only one atom of a given type is present, the subscript 1 is written.

Explanation:

1. There are about 118 known elements.
2. Compounds are made by combining atoms of elements.
3. Nine elements account for about 98% of Earth's crust, oceans, and atmosphere. They are oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, and hydrogen.
4. The elements in living matter are different from those in Earth's crust. Oxygen, carbon, hydrogen, and nitrogen are the most abundant elements in living - matter.
5. The top ten elements in the human body are oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, and chlorine.
6. Each element has a name and a symbol.
7. Oxygen symbol is O, Krypton symbol is Kr.
8. Gold's symbol Au is from the Latin 'aurum', Lead's symbol Pb is from the Latin 'plumbum'.
9. The law of constant composition states a given compound always has the same proportion by mass of the elements of which it is composed.
10. Dalton's atomic theory: All elements are composed of atoms. All atoms of a given element are identical. Atoms of different elements are different. Compounds consist of the atoms of different elements. Atoms are not created or destroyed in a chemical reaction.
11. A compound is represented by a chemical formula which shows the kind and number of atoms present. In glucose \(C_6H_{12}O_6\), there are 12 hydrogen atoms.
12. Each atom is represented by its element symbol. The number of each type of atom is indicated by a subscript written to the right of the element symbol. When only one atom of a given type is present, the subscript 1 is not written.

Answer:

1. 118
2. atoms
3. 98%; oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, hydrogen
4. different; abundant
5. oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sulfur, sodium, chlorine
6. name; symbol
7. O; Kr
8. aurum; plumbum
9. proportion; elements
10. atoms; identical; different; different; not
11. kind; number; 12
12. symbol; subscript; symbol; not