Answer:
7
Explanation:
A substance that is neither acidic nor basic is neutral. The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral.
Answer:
Average speed is 60 km/hour
Explanation:
When we need to calculate average speed, we use this equation:

Where:
position at the beginning
at the end


Then: 

Finally V = 60 km/hour
The wavelength of a wave (λ) is given by λ

where c is the wave speed and f is the frequency
We have
. So,
.
. So
.
Thus we can convert the units of the given quantity.
That is,
.
The quantity is converted to the required units.
Answer: a) Observation
b) observation
c) observation
d) observation
e) inference
f) inference
g) inference
h) inference
Explanation:
observation: The photosphere is made mostly of hydrogen and helium,The photosphere emits mostly visible light,The corona is hotter than the photosphere, The Sun emits neurtrinos
inferences: The Sun generates energy by fusing hydrogen into helium,The core temperature is 10 million k, The convection zone is cooler than the radiation zone,The composition of the photosphere is the same as that the gas cloud that have birth to our solar system.