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OLEGan [10]
3 years ago
15

For a comparative or experimental investigation, scientists often make a testable ___ about a scientific question, and then they

test it in the investigation. A. Control B. Hypothesis C. Procedure D. System
Chemistry
1 answer:
Morgarella [4.7K]3 years ago
8 0

Answer:

B. Hypothesis

Explanation: A hypothesis is a guess of what will or might happen before an experiment.

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29. Ammonia is formed with one nitrogen and three hydrogen atoms. What is the electron configuration of nitrogen? How
masya89 [10]

Answer:

<u>One lone-Pair is present in Ammonia</u>

<u></u>

Explanation:

The number of valence electron in N = 5

The number of Valence electron in H = 1

The formula of ammonia = NH3

Total valence electron in ammonia molecule = 5 +3(1) = 5+3 = 8

The lewis structure suggest that :

Nitrogen completes its octet by sharing the electron pair with 3 hydrogen atoms.

3 electron of Nitrogen are involved in sharing with Hydrogen

So,<u><em> remaining two electron are left non-bonded</em></u> . Hence they exist as lone- pair

So, there is only 1 lone pair in the ammonia molecule .

The shape of NH3 is bent according to VSEPR theory . This is so because the presence of 1 lone pair causes more repulsion and occupy more space.

Thus the lone pair is changing the shape of the ammonia molecule . It also increase the dipole moment of the molecule , which gives polarity to it.

5 0
4 years ago
Which part of a nuclear power plant spins to produce mechanical energy?
OLga [1]
The turbine since the definition of this word is <span> a machine for producing continuous power in which a wheel or rotor, typically fitted with vanes, is made to revolve by a fast-moving flow of water, steam, gas, air, or other fluid. </span>
7 0
3 years ago
The atomic symbol Superscript 206 subscript 82 upper P b. represents lead-206 (Pb-206), an isotope that has 82 protons and 124 n
Serggg [28]

Answer:

\left \{ {{y=206} \atop {x=82}}Pb \right.

Explanation:

isotopes are various forms of same elements with different atomic number but different mass number.

Radioactivity is the emission of rays or particles from an atom to produce a new nuclei. There are various forms of radioactive emissions which are

  • Alpha particle emission  \left \{ {{y=4} \atop {x=2}}He \right.
  • Beta particle emission    \left \{ {{y=0} \atop {x=-1}}e \right.
  • gamma radiation             \left \{ {{y=0} \atop {x=0}}γ \right.

in the problem the product formed after radiation was Pb-206. isotopes of lead include Pb-204, Pb-206, Pb-207, Pb-208. they all have atomic number 82. which means the radiation cannot be ∝ or β since both radiations will alter the atomic number of the parent nucleus.

Only gamma radiation with \left \{ {{y=0} \atop {x=0}}γ \right. will produce a Pb-206 of atomic number 82 and mass number 206 , since gamma ray have 0 mass and has 0 atomic number.equation is shown below

\left \{ {{y=206} \atop {x=82}}Pb\right ⇒ \left \{ {{y=206} \atop {x=82}}Pb\right +  \left \{ {{y=0} \atop {x=0}}γ\right.

Thus the atomic symbol is \left \{ {{y=206} \atop {x=82}}Pb\right

8 0
3 years ago
Read 2 more answers
Can u help me out its <br>a quick question<br>​
tia_tia [17]

The second one is the way to go.

5 0
3 years ago
What would A be? HELP ASAP
Minchanka [31]
Si has 4 available elections. Each Cl has 7.
7 x 4 = 28 + the 4 from your Si gives the total of 32 total electrons.
6 0
3 years ago
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