Complete question:
A student is working on a lab where they are trying to identify an unknown substance. The student decides to smell the solution by taking a big breath over the test tube. They immediately start to cough and their lungs are burning.
Answer and Explanation:
Many chemicals might be recognized by their smell. Some of them might be inoffensive, some others might cause slight damage and some others might be very harmful to the person that inhales them.
In the exposed example, the solution probably damaged the respiratory tract, causing inflammation and irritation.
There are some issues to take into account to avoid an accident by inhaling a chemical:
<u>Precaution</u>:
- Study the security rules of the laboratory
- Always read the label of the substance
- Ask the teacher or the person in charge, about the correct procedure
- Proceed in the correct way, by driving the smelly vapors with your hand toward your nose. Never breathe directly over the test tube.
In case of accidents by inhaling you should:
<u>Response:</u>
- Take the affected person out of the laboratory
- Look for an airy place where the affected person might breath
- Call an emergency service
- Explain exactly what the affected person did and the chemicals that the person inhaled.
Answer:
b. Only about one-half of the world's population relies on sunlight to maintain adequate vitamin D nutrition
Explanation:
Dark skin pigments slow down the synthesis of vitamin D, so black people need to spend more time in the sun to absorb enough vitamin D, so the letter A is incorrect.
Prolonged exposure to sunlight degrades the precursor of vitamin D, whereas prolonged exposure to sunlight produces vitamin D3, which acts to regulate heart function and blood pressure. With this we can conclude that the letter C is also incorrect.
Vitamin D deficiency is not caused by calcium deficiency, on the contrary, vitamin D deficiency is a cause of calcium deficiency. In addition, summer vitamin D synthesis stocks are usually not sufficient to meet summer vitamin D requirements. That is why the letter D is also incorrect.
We can conclude, then, that the correct answer is the letter B. The main source of vitamin production is through sun exposure, because type B ultraviolet rays (UVB) are able to activate the synthesis of this substance. Some foods, especially fatty fish, are sources of vitamin D, but the sun is responsible for 80 to 90% of the vitamin the body receives. It can also be produced in the laboratory and given as a supplement when there is a deficiency and for the prevention and treatment of a variety of diseases.
There more bones than muscles so it’s false
