Topic content:
There are more than 50 elements in the human body. When the elements needed by the human body are insufficient from food, they can be supplemented by food additives and health care agents, such as calcium supplements, zinc supplements or iodized salt
(1) The calcium, zinc and iodine in calcium supplements, zinc supplements and iodized salt mentioned above refer to ______ (fill in the serial number)
A、 Simple substance B, atom C, ion D, element
(2) Calcium carbonate can be used as a calcium supplement. Although it is insoluble, it can be converted into soluble calcium salt and absorbed by the human body after taking it. The chemical equation of its reaction is ______. People take calcium supplements to prevent diseases such as ______. In order to improve the calcium supplement effect, taking this calcium supplement often requires cooperation
Take vitamin D, which belongs to ______ of the six major nutrients
(3) The mass fraction of calcium element in a calcium supplement (the effective component is calcium carbonate, and the other components do not contain calcium element) is 24%, so the mass fraction of calcium carbonate in the calcium supplement is ______
Best answer:
(1) Both atoms and ions belong to microscopic concepts. The chemical properties of calcium are quite active. What the human body lacks or supplements are elements, so the answer is: elements.
(2) The main component of human gastric juice is hydrochloric acid. Calcium carbonate will react with hydrochloric acid to convert into soluble calcium salts. Calcium carbonate reacts with hydrochloric acid to generate calcium chloride, water and carbon dioxide.
So the answer is: CaCO3+2HCl=CaCl2+H2O+CO2 ↑.
Calcium makes bones and teeth have hard structural scaffolds. Lack of calcium will lead to rickets, stunting and osteoporosis, so the answer is rickets.
Vitamin D belongs to the six major nutrients, so the answer is: vitamin
(3) The content of calcium element in calcium carbonate is 40100 × 100%=40%, so the mass fraction of calcium carbonate is 24% 40% × 100%=60%, so the answer is 60%
Answer analysis:
forty thousand and one hundred
Test core:
The existence form of elements in human body:
① Carbon, hydrogen, oxygen and nitrogen mainly exist in the form of water, sugar, protein, vitamins and fat.
② Other elements mainly exist in aqueous solution in the form of inorganic salts.
③ Calcium element mainly exists in the form of hydroxycalcium phosphate [Ca10 (PO4) 6 (OH) 2] crystal.