<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />

# Percent Composition

## Calculating the percentage by mass of each element in a compound.

Estimated14 minsto complete
%
Progress
Practice Percent Composition

MEMORY METER
This indicates how strong in your memory this concept is
Progress
Estimated14 minsto complete
%

Credit: Jamie McCaffrey
Source: http://www.flickr.com/photos/15609463@N03/9659294178/

Many people enjoy the outdoors. Some like cooking hot dogs over a campfire (or a grill in the back yard). Others like to throw on a backpack and hike. The truly dedicated campers hike into wilderness areas, bringing their food along with them. Since cans weigh a lot and fresh foods (such as meats) would spoil, dehydrated foods are very popular. Just add water when it’s time to cook (well, there is a little more to it than that), and you have a hot meal ready to eat.

#### News You Can Use

• The label on the frozen chicken breast package reads “Contains up to 15% water and kosher salt.” So a one-pound breast is actually only 0.85 pounds. That may not matter in terms of cooking since so many of us vary the amount of meat that is used anyway. Frozen boneless breasts may cost \$2.00/pound, so you are paying thirty cents for the water. The advantage is that the chicken is less likely to dry out and will have better flavor since the water/salt combination helps tenderize the meat.
• Meals Ready to Eat (MREs) are an innovation developed by the military in the early 1980s. These dehydrated foods made it possible for a person to carry more food due to the lighter weight of the packages as compared to their canned counterparts. Water could be added and a meal prepared. Development of a flameless heater (based on an exothermic reaction) permitted the meals to be warmed, Currently there are two dozen basic menus and over a hundred individual items available. MREs are now commercially available for camping, emergencies, and other related uses.
• Credit: Virtualtitus
Source: http://www.flickr.com/photos/78364610@N04/6870295872/

Meal Ready-to-Eat are available for vegetarians as well [Figure2]

• Hydration is an important part of good health. Many people, especially children and the elderly, need to be careful about their water intake. A good rule of thumb (although not supported by a lot of medical data) is to drink eight 8-ounce glasses of water every day. This will vary somewhat based on body weight and level of activity. Very active individuals will require more water that those who are more sedentary.
• Watch a video about analysis of a hydrate at the link below:

#### Show What You Know

1. What is one drawback of purchased dehydrated foods?
2. How much water should be added to dehydrated food to prepare it?
3. What are symptoms of dehydration?
4. What is potassium alum used for?
5. What does water do for the body?

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes