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3 years ago

How many atoms is 50 g of He?

1 answer:

6 0

Atomic <span>mass He = 4.002 u.m.a

4.002 g --------------- 6.02x10</span>²³ atoms
50 g ------------------ ? atoms

50 x ( 6.02x10²³) / 4.002

= 3.01x10²⁵ / 4.002

= 7.52x10²⁴ atoms of He

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Ans: B) semiconductor

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Answer:

The mean is $x=0.503\frac{mg}{L}$

The 90% confidence interval is:

$i_{0.90}=[0.492\frac{mg}{L},0.514\frac{mg}{L}]$

Explanation:

1. First organize the data:

$x_{1}=0.487$

$x_{2}=0.487$

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The formula to find the confidence interval is:

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$z_{0.05}=1.645$

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$i_{0.90}=[0.503-1.645*(\frac{0.015}{2.236})]$

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$i_{0.90}=[0.492,0.514]$

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