1. all elements are made of small particles called atoms
2. atoms of one element are identical in their properties, different atoms from different elements differ in properties
3. chemical reactions consist of atoms rearranging in whole number ratios
4. atoms can not be subdivided, created, or destroyed
Answer:
Percent composition tells you which types of atoms (elements) are present in a molecule and their levels. Percent composition can also tell you about the different elements present in an ionic compound as well.
Answer: Formation of hydrogen iodide will occur.
Explanation:
When molecule of hydrogen gas 
and molecule of iodine gas 
collide with proper orientation and with sufficient amount of energy. This collision of the two different molecules of gases will result in the formation of hydrogen iodide.
The balanced chemical equation of the reaction will written as:
Yes, because of the reaction causes
Answer:
5. +5
6. +7
Explanation:
The oxidation state can be obtained as follow:
5. Oxidation state of oxygen, O = –2
Oxidation state of phosphorus, P =?
P3O10 = –5
3P + 10O = –5
3P + (10 x –2) = –5
3P – 20 = –5
Collect like terms
3P = –5 + 20
3P = 15
Divide both side by 3
P = 15/3
P = +5
Therefore, the oxidation state of P in P3O10^5- is +5
6. Oxidation state of oxygen, O = –2
Oxidation state of manganese, Mn =.?
Mn2O7 = 0
2Mn + 7O = 0
2Mn + (7 x –2) = 0
2Mn – 14 = 0
Collect like terms
2Mn = 14
Divide both side by 2
Mn = 14/2
Mn = +7
Therefore, the oxidation state of Mn in Mn2O7 is +7
