Certain Planes of a Crystal of Halite Have a Spacing

question 2

Multiple Choice

Certain planes of a crystal of halite have a spacing of 0.399 nm. The crystal is irradiated by a beam of x-rays. First order constructive interference occurs when the beam makes an angle of 20° with the planes. What is the wavelength of the x-rays?

• A) 0.14 nm
• B) 0.17 nm
• C) 0.21 nm
• D) 0.24 nm
• E) 0.27 nm

Describe the lifecycle transitions and dependencies in nonvascular and vascular plants.

Explain the significance of heterosporous and homosporous conditions in plant evolution.

Recognize patterns and significance of plant morphology evolution, including vascular structures.

Understand the ecological and evolutionary significance of plants during the Carboniferous period.

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Definitions:

Cosine

A mathematical function used in trigonometry to define the ratio of the adjacent side to the hypotenuse of a right-angled triangle.

Sine

A trigonometric function denoting the ratio of the length of the side opposite to a given angle to the length of the hypotenuse in a right-angled triangle.

Pulsating

A periodic variation in magnitude or intensity, often used to describe waveforms or signals.

Peak-to-peak

A measure of the amplitude of a waveform, indicated by the difference between its maximum and minimum values.