Answer:
D. Radar uses radio, and the siren uses sound waves.
Explanation:
The main difference between the siren passing by and the radar is that radar uses radio waves and siren uses sound waves.
- Sound waves are mechanical waves which requires a material medium for their propagation.
- In a vacuum, the sound waves cannot pass through freely.
- Radar is an electromagnetic wave.
- It is particular of radio waves origin.
- Such waves do not require a material medium for their propagation and hence can be transmitted through a vacuum.
Answer:
Water H2O
Explanation:
A solvent is defined as being able to dissolve other substances, the fertilizer is being dissolved in the water prior to watering the plants, therefore the water is the solvent in this case.
Answer:
https://socratic.org/answers/220339
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Explanation:
The answer is 267.93 g
Molar mass of CaBr2 is the sum of atomic masses of Ca and Br:
Mr(CaBr2) = Ar(Ca) + 2Ar(Br)
Ar(Ca) = 40 g/mol
Ar(Br) = 79.9 g/mol
Mr(CaBr2) = 40 + 2 * 79.9 = 199.8 g/mol
The percentage of Br in CaBr2 is:
2Ar(Br) / Mr(CaBr2) * 100 = 2 * 79.9 / 199.8 * 100 = 79.98%
Now make a proportion:
x g in 79.98%
335 g in 100%
x : 79.98% = 335 g : 100%
x = 79.98% * 335 g : 100%
x = 267.93 g
Answer:
Threatened Species: A threatened species is a species at risk but not yet endangered. California sea otters were classififed as a threatened species. Laws were passed to protect the otters and now they have increased their population size.
Invasive Species: One of the main causes of extinction and endangered species is the introduction of an exotic species. New exotic species are called invasive species. Invasive species can disrupt food chains, carry disease, prey on native species directly, and out-compete native species for limited resources, like food.
Extinction: If a population decreases too much in numbers, they disappear. Extinct species mean that the species has died out and no individuals left. An example of extinction: New Zealand was once home to a bird called the Giant Moa. Humans settled as their population increased the Moa population decreased. The species is now extinct.
Explanation:
