<h3>
Answer: D) all of the above</h3>
Explanation:
The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.
Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.
When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.
In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)
So that's why the answer includes A, B and C.
<span>C. New substances are always produced in chemical changes, which is not the case with physical changes. For example, when you cut wood into smaller pieces you still have wood in the end. But, with a chemical change you change the substance's whole composition. For example when you add two hydrogen's to one oxygen you have water and it can't break down from that. </span><span />
Answer:
9.9 moles of Ag₂S contain 9.9 moles of sulfur.
Explanation:
Given data:
Number of moles of Ag₂S = 9.9 mol
Number of moles of Sulfur = ?
Solution:
One mole of Ag₂S having 1 mole of sulfur.
In 9.9 moles:
9.9 moles × 1 = 9.9 moles
So 9.9 moles of Ag₂S contain 9.9 moles of sulfur.
Explanation:
The idea here is that you need to use the Periodic Table of elements to find the mass number of the most common isotope of phosphorus, P.
Even though two grams seemed to disappear or vanish, the law of conversation of mass still holding true. Mercuric oxide, when heated, forms a gas of mercury and oxygen. During the investigation, some gas could have escaped or evaporated.
