Answer:
correct answer is option d (Light emitted by an element produces a unique identifying spectrum.)
Explanation:
Each element has different atomic number and atoms of an element can radiate a certain amount of energy. Different elements have different atomic spectrum and it can be used to determine the composition of a material.
When atoms are excited to higher energy state after some time they came back to lower state by emitting their excess energy in the form of light. This light has certain wavelength. This emitted light can be seen as a series of different colored lines and between two colored lines there is a dark space. This series of colored lines is called a line spectra or atomic spectra.
After the great 1906 San Francisco earthquake, geolophysicistHarry Fielding Reid examined the displacement of the ground surface along the San Andreas Fault. He concluded that the quake must have been the result of the elastic reboundof the strain energy in the rocks on either side of the fault.
strain energy is 0. 5x force x (compression) X (compression)
There is a lot of force and a bit of compression when rocks squash up against other rocks causing earthquakes
Answer:
Explanation:
In optics, the refractive index of a material is a dimensionless number that describes how fast light travels through the material. It is defined as where c is the speed of light in vacuum and v is the phase velocity of light in the medium or for short the ratio of the velocity of light in a vacuum to its velocity in a specified medium.
Answer:
Magnetic letters Screws and bolts
Explanation:Magnetic letters have to be magnetic so they can stick to things like walls and fridges. Screws and bolts are magnetic becaus they become easier to to screw onto things since the tool that you use to screw it in is also magnetic.
