Elements & Compounds
Define difference between elements and compounds.
Element is same type of atom through out.
Compounds have to have at least two DIFFERENT elements chemically bonded together.
List three properties of metals?
Luster (shiny)
malleable
conductor
Ductile
Bends easily
What is the best evidence that a chemical reaction occurs when wood is burned?
A. The shape of the wood after burned
B. Oxygen is present
C. Ash is produced.
D. Wood is made up from more than one atom
C. Ash is produced.
What is the formula to density?
Density=mass/volume
Which of the following answer choices ONLY contain elements?
A. S, Fe,O2, Sr, and Al
B. S, O2, LiF
C. N2O, LiF, and H2O
D. NaCl, Fe, O
A. S, Fe,O2, Sr, and Al
List three properties of non metals.
Dull (not shiny)
brittle
insulators (poor conductors)
A physical change is when you change -
A. the presence/shape of object
B. the chemical formula of something
A.
If you are looking a cylinder of water, and a metal cube is at the bottom and a bottle cap is at the top, which one has the most density?
metal cube because it sunk to the bottom
Which answer choice contains ONLY chemical compounds?
A. NH3, KNO3, Hg, Fe
B. H2O, NaCl, FeO
C. NH3, FeCl, O
D. Fe, Cl, NaCl
B. H2O, NaCl, FeO
Which of the following choices would be correct when describing iron (Fe)-
A. iron is brittle and a good conductor
B. iron is malleable and a good conductor
C. iron is ductile and is an insulator
D. iron is brittle and is an insulator
B. iron is malleable and a good conductor
A chemical changes produces a new-
substance.
If you place an acid tablet in a glass of water, bubbles would rise to the top. Which would be LESS dense than water?
The bubbles
How many DIFFERENT elements are involved in the reaction shown below?
C3H8 + 5O > 3CO2 + H2O
three
Which of the following answer choices would correctly describe a metal?
A. does not conduct electricity and breaks easily.
B. does conduct electricity and bends easily
C. does not conduct electricity and shatters easily
D. does not conduct electricity and is shiny
B.
Which of the following would be an example of a chemical change?
A. a piece of paper that is ripped
B. a piece of wood that is chopped
C. a rotten apple
D. an apple cut into slices
C. a rotten apple
What is the density of an object with a mass of 21.0 grams and a volume of 7.0 cm3?
3 g/cm3
In the chemical reaction below, all three chemicals are best classified as -
CaCO > CaO + CO2
A. two elements and one compound
B. One element and two compounds
C. three compounds
D. one compound and two elements
C. three compounds
Which of the following answer choices would describe a nonmetal?
A. shiny and conducts electricity
B. Dull and broken by a hammer
C. Shiny and shaped into wire
D. Flattened by hammer and shiny
B. Dull and broken by a hammer
Give me three chemical change signs that allow you to understand that a chemical change has taken place.
ash is produced
new substance has formed.
What is the density in g/ml of a marble with a mass of 30 grams and a volume of 6 milliliters?
5g/ml