-
Are Elements heterogeneous or homogeneous
Homogeneous, they look alike throughout the sample
-
are compounds heterogeneous or homogeneous
homogeneous, they look alike throughout the sampe since there is only one substance present, even if it's a combination of elements it must be alike throughtout.
-
A generality states that all compounds containing both carbon and hydrogen burn. do octane and propane burn? (each contains only carbon and hydrogen)
Yes both burn. all organic compounds burn .
-
sodium is a very reactive metallic element: it liberates hydrogen gas when treated with water. chlorine is a yellow-green, choking gas used in WWI as a poison gas. contrast these properties with those of sodium and chlorine- sodium chloried- (table salt)
salt doesn't react with water to liberate hydrogen, it isn't reactive and isn't poisonous. it's a while solid and not a silvery metal or green gas. in short, it has it's own set of properties :. is a compound
-
TNT ius a compound of carbon, nitrogen, hydrogen and oxygen. carbon occurs in two common forms- graphite and diamond. Oxygen and nitrogen comprise over 98% of the atmosphere. Hydrogen is an element that reacts explosively with oxygen. which of the properties of the elements determines the properties of TNT?
The properties of the elements don't matter. the properites of the compound are quite independent of those of the elements. a compound has it's onw distinct set of properties. tTNT is most noted for it's explosiveness.
-
A sample contains 88.8% oxygen and 11.2% hydrogen by mass, and is gaseous and explosive at room temperature.
a) is the sample a compoud or mixture
b) after the sample explodes and cools it is a liquid, is it now a compound or mixture?
c) would it be easier to change the percentage or oxygen before or after the explosion.
- a) mixture (compound of hydrogen and oxygen with this composition (water) is a liquid under these conditions)
- b) compound
- c) before the explosion,. it is easy to add hydrogen or oxygen to the gaseous mixutre, but you can't change the composition of water.
-
what is the exception to the statment that nonmetals lie to the right of the stepped line in the periodic table?
Hydrogen
-
what is the ratio of the number of metals to the number of nonmetals in the periodic table
-
there are 109 elementts. 22 nonmetals and 87 metals so ratio is 3.95 metals per nonmetal
-
what is the symbol for:
a)iron
b) copper,
C) carbon
D) sodium
e) silver
f) aluminum
- a) Fe
- b) cu
- c) C
- d) Na
- e) Ag
- f) AI
-
name each of the following elements
a)K
b)P
c)Cl
d)H
e)O
- a) potassium
- b) phosphorus
- c) Chlorine
- d) hydrogen
- e) Oxygen
-
distinguish between a theory and a law
- Law: tells what happens under a given set of circumstances
- Theory: attempts to explain why a law happens
-
distinguish between
a) mass and matter
b) mass and weight
- a) matter is any kind of mateiral. the mass of an object depends mainly on the matter it contains it is only slightly affected by the energy in it
- b) weight is the attraction of the earth on an object. it depends on the mass of the object and its' distance to the center of the earth
|
|
