Answer:Towhen two waves if nearly same amplitude and same wavelength interfere with each other that time a new wave is formed with a different amplitude this phenomena is known as superposition. If two waves interfere with each other in same phase that time amplitude of resultant wave wave is greater than the component waves and this type of interference is known as constructive interference. And when waves suprpose in opposite phase that time amplitude of resultant wave is less than the component waves and this type of interference is known as destructive interference.
Example: light waves, water waves, sound waves etc
Water has special characteristics because liquid water is denser than ice and ice floats on top of liquid water.
Answer: Option A & D
<u>Explanation:</u>
A water molecule is formed by the covalent bonding between two atoms of Hydrogen atom with one atom of Oxygen. In water, the Hydrogen bonds are the one that keeps the water molecule intact.
When the water molecule freezes the bonding becomes weak as they are separated and set apart which makes the liquid water denser than ice. Normally a substance floats if it is less dense. Ice floats because it is less dense than water.
Under a microscope, gram-positive bacteria (when dyed with the gram stain) appear in purple-colored structures due to the peptidoglycan cell wall.
<h3>What are gram-positive bacteria?</h3>
Gram-positive bacteria are microorganisms (bacteria) that may be colored with crystal violet stain due to the presence of a peptidoglycan-based cell wall.
In conclusion, under a microscope, gram-positive bacteria (when dyed with the gram stain) appear purple-colored structures due to the peptidoglycan cell wall.
Learn more about gram-positive bacteria here:
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Answer:
The elements in each group have the same number of valence electrons. As a result, elements in the same group often display similar properties and reactivity.
The answer is the letter C
