In 1961,the Reference for the Atomic Mass Unit (Amu or U)was

question 96

Multiple Choice

In 1961,the reference for the atomic mass unit (amu or u) was changed from naturally occurring oxygen with a value of 16.000 u to one based on a single isotope of carbon (carbon-12) .Why was it changed?

• A)The atomic composition of oxygen varies depending upon its source.
• B)Carbon-12 is more common than oxygen.
• C)Carbon exists as only one isotope, carbon-12.
• D)Carbon can combine with four atoms of hydrogen to form CH₄, methane, while oxygen only combines with two atoms of hydrogen to form water, H₂O.

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Definitions:

Glomerular Capsule

The glomerular capsule, also known as Bowman's capsule, is a cup-like sac at the beginning of the tubular component of a nephron in the mammalian kidney that performs the first step in the filtration of blood to form urine.

Renocytes

Specialized cells found in certain invertebrates that are involved in the excretion process.

Cytoplasmic Extensions

Protrusions of the cell's cytoplasm that increase its surface area for absorption or movement, such as pseudopods in amoebas or axons and dendrites in neurons.

Kidney Infections

Bacterial infections that affect the kidneys, often a complication of a urinary tract infection, leading to symptoms like fever, back pain, and nausea.