The Doppler effect doesn't just apply to sound. It works with all types of waves, which includes light. Edwin Hubble used the Doppler effect to determine that the universe is expanding. Hubble found that the light from distant galaxies was shifted toward lower frequencies, to the red end of the spectrum. This is known as a red Doppler shift, or a red-shift. If the galaxies were moving toward Hubble, the light would have been blue-shifted.
Answer:
Explanation:
A pressure of 1 atm and a temperature of 0 °C is the old definition of STP. Under these conditions, 1 mol of a gas occupies 22.4 L.
1. Calculate the moles of hydrogen.
2. Calculate the number of molecules
Answer:
Energy levels
Explanation:
Elements in one row of the periodic table have the same energy levels. A row on the periodic table is the horizontal arrangement of elements. These rows are called periods.
There are 7 periods on the periodic table.
- Each elements on a period begins with an atom having one valence electrons and then ending with completely filled orbitals.
- Elements in the same period are known to have the same electronic shells which is the energy level.
- The principal quantum number of their electrons is the same.
Answer:
International System of Units (SI)
Explanation:
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