Naturally Occurring Silicon Is Composed of Three Isotopes: ²⁸Si (Atomic

question 15

Multiple Choice

Naturally occurring silicon is composed of three isotopes: ²⁸Si (atomic mass 27.98) , ²⁹Si (atomic mass 28.98) , and ³⁰Si (atomic mass 29.97) . The atomic mass of the naturally occurring isotope mixture is 28.0855. The relative percentages of ²⁸Si, ²⁹Si, and ³⁰Si are

• A) 99.7, 0.1, 0.2
• B) 92.2, 4.7, 3.1
• C) 90.2, 1.3, 8.5
• D) 80.2, 10.8, 9.0
• E) 50.4, 20.5, 29.1

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Definitions:

Pollution

The introduction of contaminants into the natural environment that cause adverse changes, affecting air, water, and soil quality.

Environmental Standard

Regulations and criteria set by authorities regarding pollutants and emissions to protect the environment and public health.

Emissions Tax

A tax on the production, sale, or use of goods that produce pollutants, intended to reduce the harm they cause to the environment.

Marginal Benefit

The added gain achieved by consuming an additional unit of a product or service.