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MariettaO [177]
3 years ago
14

How many neutrons does element X have if its atomic number is 31 and its mass number is 84?

Chemistry
1 answer:
Alex3 years ago
8 0
Atomic number is protons + electrons
Mass number is protons + neutrons
So to calculate the number of neutrons, you do
atomic number - atomic mass
31 - 84 = - 53
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John rode 3150 m at an average speed of 350 m/min.If he had ridden at average of 375 m/min instead. How much sooner would it hav
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Explanation:

Given that:

Distance traveled = 3150m

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Unknown:

Time = ?

Solution:

Speed is the rate of change of distance with time.

  it is mathematically expressed as;

     speed = \frac{distance }{time}

Initial time using speed 350m/min can be calculated by making time the subject of the formula;

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   to seconds = 9 x 60 = 540 seconds

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It could have taken 504 seconds sooner saving 36 seconds.

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7 0
4 years ago
Explain why the atomic radius of fluorine is smaller than that of lithium​
Sladkaya [172]

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Vanyuwa [196]

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