Answer:
169
Explanation:
Mass number is the number of protons and the number of neutrons combined.
70 + 99 = 169
The Patch's area of the space shuttle in km² is 2.07 × 10⁻⁹ km²
Given, that a space shuttle requires a 20.7 cm² patch
We have to convert the patch's area from cm² into km².
Unit conversion is a method in which we multiply or divide with a particular numerical factor and then finally round off to the nearest significant digits.
Patch area of the space shuttle is 20.7 cm²
1 cm = 0.00001 km
or, 1 cm² = (0.00001 km)²
or, 1 cm² = 10⁻¹⁰km²
20.7 cm² = 20.7 × 10⁻¹⁰km²
20.7 cm² = 2.07 × 10⁻⁹ km²
The patch area in square kilometers is 2.07 × 10⁻⁹ km²
To learn more about unit conversion, visit: brainly.com/question/11543684
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Answer:
I don't know about the oil part but "It is important to develop alternative
sources of energy because scientists are unsure of how long they will last"
Explanation:
Because they are nonrenewable resources, it takes hundreds to millions of years for them to be made again naturally. Once we're out, we're out. It would be a huge issue of that happened because Oil, Petroleum, and Natural Gas (all fossil fuels) are needed for heating, gas stoves, etc.
Answer:
It gives the number of protons in the nucleus of each atom of that element.
Explanation:
Aldehydes may oxidize to form carboxylic acid <span>exception to oxidizing formaldehyde with strong oxidizing agent.
HCHO + 3[O] = CO</span>₂ + H₂O
