Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum
Initial kinetic energy
Final kinetic energy
So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
In a mixture, there will be a solute and solvent. The hydrogen and oxygen are still two different atoms that just mixed together. But in a compound, the hydrogen and oxygen have a bond, making a new and bigger molecule. A mixture can easily be separated by physical means but a compound isn't.
Answer:
The brightness of bulb 1 dies because it is switched off.
The mass number is the total number of protons and neutrons within an atom and since we know that the unknown element has 6 neutrons, we can simply subtract the number of neutrons from the mass number to get the number of protons.
17 - 6 = 11
There are 11 protons in this unknown element.
Extra:
The number of protons (+) and electrons (-) are equal in a neutral atom so since you know that there are 11 protons you also know that there are 11 electrons. On the periodic table, the element with 11 electrons is Na or Sodium.
Hope this helps! :)
