Answer:
Correct option: D (both A and B)
Explanation:
Key things of bohr's model is that electrons occupy fixed orbital and required fixed amount of energy and electron must be in specific orbital and have precise amount of energy for that orbit
Niels bohr proposed a hydrogen atom model which explains the spectrum of hydrogen and he assumed that electron of hydrogen revolves around the nucleus in the circular orbit and bohr's model is valid only for single electron species.
statement of option A and B are correct
hence D is correct
Answer:
1gram of water
Explanation:
First balance the equation
Ch4+2O2>CO2+2H2O
Ratio is 1:2
500×10-3what about 2?
500×10-3×2=1g
1g of water
Answer:
A
Explanation:
the correct answer is A
This is the sidereal month. It is measured against the background stars. However, the Earth is also orbiting the Sun, and the moon needs extra time to catch up to its previous position relative to the Sun.
Answer: True
Explanation:
Physical change is a change in which there is no rearrangement of atoms and thus no new substance is formed. There is only change in physical state of the substance.
Chemical change is a change in which there is rearrangement of atoms and thus new substance is formed. There may or may not be a change in physical state.
Slowly heating butter in a pan until it changes from a solid to a liquid is an example of a physical change is true as solid changes to liquid state and there is no breaking or making of chemical bonds.
4) their metallic properties increase and their atomic radii increase.
