Answer:
D. 100 cm
Explanation:
The speed of a wave is the wavelength times the frequency.
v = λf
Wave A and B have the same speed, so:
λf = λf
(50 cm) (7000 Hz) = λ (3500 Hz)
λ = 100 cm
Answer:
it's because some versions have more steps and others have less
The complete statement is "chemical properties can be observed only when the substance in a sample of matter are changing into different substance".
It states a key concept in chemistry.
A chemical property is the ability of a substance, element or compound, to <em>transform</em> into other substances either <em>by decomposing or by combining</em> with one or more substances.
This transformation is defined as chemical reaction.
During chemical reactions some chemical bonds are broken and others are formed leading to the formation of one or more different substances called products.
Some examples of chemical properties are: reactivity with oxygen, reactivity with water, acidity, basicity, oxidation, reduction. The only way to tell if a substance has certain chemical property is by letting it react and so observe the change of the original substance into one or more different substances.
<h2>
Answer: can see</h2>
Explanation:
The portion visible by the human eye of the electromagnetic spectrum is between 380 nm (violet-blue) and 780 nm (red) approximately. Which means this part of the spectrum is located between ultraviolet light and infrared light.
Note the fact only part of the whole electromagnetic spectrum is visible to humans is because the receptors in our eyes are only sensitive to these wavelengths.
Therefore:
<h2>The visible spectrum refers to the portion of the electromagnetic spectrum that <u>we </u><u>
can see</u></h2>