Multiple Choice
In the chemical formula 5Mg3(PO4)2, what does the subscript '2' after the parentheses indicate?
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1. Intro to General Chemistry
Chemical Properties
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About 96% of the dry cell weight in living organisms is composed of which elements?
A
Phosphorus, sulfur, chlorine, and iron
B
Sodium, potassium, calcium, and magnesium
C
Copper, zinc, iodine, and selenium
D
Carbon, hydrogen, oxygen, and nitrogen
Verified step by step guidance1
Understand that the question is about the elemental composition of living organisms, specifically the elements that make up about 96% of the dry cell weight.
Recall that the four most abundant elements in living organisms are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). These elements are fundamental to the structure of biomolecules such as proteins, nucleic acids, carbohydrates, and lipids.
Recognize that other elements listed, such as phosphorus, sulfur, chlorine, iron, sodium, potassium, calcium, magnesium, copper, zinc, iodine, and selenium, are important but present in much smaller amounts and do not collectively make up the majority of dry cell weight.
Conclude that the correct group of elements making up about 96% of the dry cell weight in living organisms is carbon, hydrogen, oxygen, and nitrogen.
This understanding is based on the elemental composition of biological macromolecules and the typical elemental analysis of cells.
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