Answer:
7
Explanation:
The coefficient is the number in front of the chemical symbol.
Answer: Time taken by a sound impulse to travel through an aluminum rod 25 kilometers long is 4.9 seconds.
Solution:
Length of aluminium rod = 25 km = 25000 m (1 km=1000 m)
Time taken by sound to travel through aluminium = 5100 m/s (from the table given)

time taken =
Hence, the correct option is 4.9 seconds.
Mendel's laws of hereditary are
1) Segregation
2) Independence
3) Dominance
Since you putting them from third to first, your
answer would be A. Dominance, Independence, Segregation.
Correct Answer: option 1 i.e. C
Reason:
The the compound of interest i.e. XCl4, since there are 4 Cl atoms bonded to X. This signifies that the valency of X is 4.
There atomic number of C is 6. It's electronic configuration is giving by 1s2 2s2 2p2. Thus, there are 4 electrons in valence shell of C. This signifies that valency of C is 4. Hence the compound present in present case is CCl4.
9 x 3 = 27
27 moles of O reacted
27 / 2 = 13.5 O2 reacted
round up to 14 moles of O2