Krypton is the least metallic. Because it is a noble gas. The elements go from left to right in order of most to least metallic. Krypton is the farthest right out of all of the elements you listed.
Answer: person C.
Explanation:
1) The frequency of the sound wave is perceived or detected as the pitch of the sound.
And the higher the frequency the the higher the pitch.
2) When a sound source is in motion there is an apparent change in the pitch perceived. This is the Doppler effect, which is defined as the change in the perception of the pitch in virtue of the relative motion between the listener and the emitter of the sound.
If the source of the sound is moving toward the listener, the pitch will be higher that if the sound is at rest. If the source of the sound is moving away from the listener, the pitch will be lower.
That is because the the motion of the emitter increases (or decreases, depending on whether the emitter is moving toward or away the listener) the speed of the sound waves and they arrive more frequently (or less frequently).
Then, since the sound is emitted by the motorbike and it is moving toward the person C, he will hear the highest pitch.
Answer:
C) A ratio based on the mass of a carbon-12 atom
Explanation:
For each element, there is a characteristic number of protons, this number represent a type of atom and its called the atomic number
On the other hand we have the number of neutrons, and for one element which difers only on the number of neutrons, we have different isotopes from one element.
Together, protons and neutrons define the mass number
One property linked with the mass number, is the atomic mass, which is formerly expressed as "uma" (atomic mass unit)
By definition, one atom of carbon-12 (with 6 neutrons) has an atomic mass of 12 umas
Initially, the spring stretches by 3 cm under a force of 15 N. From these data, we can find the value of the spring constant, given by Hook's law:

where F is the force applied, and

is the stretch of the spring with respect to its equilibrium position. Using the data, we find

Now a force of 30 N is applied to the same spring, with constant k=5.0 N/cm. Using again Hook's law, we can find the new stretch of the spring:
Answer:
option A
Explanation:
Given,
wavelength of light,
refractive index of gasoline, n₁ = 1.40
Refractive index of water, n₂ = 1.33
thickness of the film, t = ?
Condition of constructive interference is given by

For minimum thickness of the film m = 0
From the question we can clearly observe that phase change from gasoline to air
so, n = 1.4


Hence, the correct answer is option A