Nuclear reactors use hydrogen and they are an up and coming energy source.
There are also hydrogen fuel cells.
Given: The population density of frogs in a portion of a pond is 12 frogs per square meter. The size of the entire pond is 370 square meters.
To find: The total population size of the frogs in the pond.
Method: Using unitary method of proportions
Solution:
Let p be the density of the frogs present per square meter.
Let A denote the total area of the pond.
∴ p = 12 frogs/m² and A = 370 m²
The total number of frogs in the pond is given by,
Therefore, there are 4440 frogs in the pond.
Answer:
A, the populations of producers and decomposers should be stable
Explanation:
The other three do not fit, only reasonable one is A
Answer:
Peanut butter
Explanation:
Peanut butter's vitamins are 19.5% vitamin E. Other condiments and spreads are usually under this.