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balu736 [363]
4 years ago
5

What element is this? How do you know?

Chemistry
1 answer:
Gnom [1K]4 years ago
8 0

This element is Helium. This is because it has two protons and two neutrons in its nucleus. this makes it have the atomic mass of approximately four atomic mass units. It also has two electrons in the first energy level. . It is therefore a noble gas since this is the only energy level and it obeys the 2n² rule for the filling of energy levels. n in this case is 1 making the maximum number of electrons in the first energy level to be 2.

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A Doppler radar _________. *
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1.) can detect precipitation as well as the movement of small particles which can be used to approximate wind speed.
5 0
3 years ago
What are 3 general rules to predict the stability of an isotope
Mashcka [7]
<span><span>1) Calculate the total number of nucleons (protons and neutrons) in the nuclide
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2) Are there a magic number of protons or neutrons?
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8 0
3 years ago
The density of copper is 8.94 g/cm3. An irregular shaped sample of metal is 14 g and displaces a volume of 2.98 mL. (a) Find the
Vedmedyk [2.9K]

Explanation:

<h2>(a).</h2>

The density of a substance can be found by using the formula

density =  \frac{mass}{volume}  \\

From the question

mass of metal = 14 g

volume = 2.98 mL = 2.98 cm³

It's density is

density =  \frac{14}{2.98}  \\  = 4.69798657...

We have the answer as

4.70 g/cm³

<h2>(b).</h2>

The metal is not copper since it's density is less than that of copper.

Hope this helps you

8 0
3 years ago
A brick measures 0.018 dam by 6.5 cm by 17.3 cm. What is the volume of the brick in cubic centimeters
erastova [34]

Answer:

volume of brick= length × breadth × height

=0.000018 ×6.5×17.3

=

7 0
3 years ago
A chemist measures the amount of hydrogen gas produced during an experiment. She finds that 264. g of hydrogen gas is produced.
Lesechka [4]

Answer:

The answer is 130.953 g of hydrogen gas.

Explanation:

Hydrogen gas is formed by two atoms of hydrogen (H), so its molecular formula is H₂. We can calculate is molecular weight as the product of the molar mass of H (1.008 g/mol):

Molecular weight H₂= molar mass of H x 2= 1.008 g/mol x 2= 2.01568 g

Finally, we obtain the number of mol of H₂ there is in the produced gas mass (264 g) by using the molecular weight as follows:

mass= 264 g x 1 mol H₂/2.01568 g= 130.9731703 g

The final mass rounded to 3 significant digits is 130.973 g

4 0
3 years ago
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