Answer:
The answer is (3) 3 × 12.4 hours
A.Calcium and magnesium dissolve in water.
B.Calcium and magnesium evaporate on contact with the walls of the pipe.
C.Calcium and magnesium form precipitates of their respective oxides.
It's C, calcium and magnesium form precipitates of their respective oxide
The statement 'Calcium and magnesium form precipitates of their respective oxides' best describes the chemical change as it involves a reaction that transforms the calcium and magnesium into new compounds, their oxides, which can clog pipes.
The statement that best describes this change as a chemical change is C. Calcium and magnesium form precipitates of their respective oxides. This represents a chemical change because it involves a reaction that transforms the calcium and magnesium into new substances - their oxides. Here's how it works: in the presence of oxygen, calcium and magnesium in hard water can undergo an oxidation process. During this oxidation, the calcium becomes calcium oxide and the magnesium becomes magnesium oxide. These oxides are less soluble in water and form precipitates, which can accumulate and clog the pipes.
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B.triglyceride
C.protein
D.Polypeptide
Answer
monosaccharide
Explanation
Carbon dioxide, ethanol, and energy
Lactic acid and energy
Glucose, oxygen, and energy
Explanation:
Atomic number is defined as the sum of total number of protons present in an atom. Each element has different atomic number.
Whereas mass number is the sum of total number of both protons and neutrons present in an element.
For example, an atom with mass number as 15 and has atomic number 7. Then it means it has 7 protons.
Therefore, number of neutrons present in it will be calculated as follows.
Mass number = no. of protons + no. of neutrons
15 = 7 + no. of neutrons
no. of neutrons = 15 - 7
= 8
Thus, we can conclude that the number of neutrons is calculated as mass number minus total number of protons present in the atom.