Please help asap 18 points if help and right answer please

Lithium = 8%

Bromine = 92%

Explanation:

To calculate percent composition, you must:

- Calculate the molar mass.

- Divide the subtotal for each element's mass by the molar mass.

- Convert to a percentage

With that being said, given LiBr (Lithium Bromide), calculate the molar mass:

Lithium has an atomic weight of 7, and there is one Lithium atoms in LiBr. Bromine has an atomic weight of 80, and there is one Bromine atom in LiBr:

Add the two products:

The molar mass of LiBr is about 87 grams.

With that information, divide the subtotal of Lithium by the molar mass, and then multiply by 100 to convert to a percentage:

×

8.0459%

(Round to nearest percentage):

8%

Therefore, the percent composition of Lithium in the compound Lithium Bromide is about 8%.

Now, divide the subtotal of Bromine by the molar mass, and then multiply by 100 to convert to a percentage:

×

91.9540

(Round):

92%

Therefore, the percent composition of Bromine in the compound Lithium Bromide is about 92%.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the answer your looking for is c).