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enyata [817]
3 years ago
6

How can you determine the number of valence electrons an atom has

Chemistry
1 answer:
Luden [163]3 years ago
6 0

For neutral atoms, the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.


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Part A
Roman55 [17]

These are two questions and two answers

Question 1.

Answer:

  • <u>7.33 × 10 ⁻³ c</u>

Explanation:

<u>1) Data:</u>

a) m = 9.11 × 10⁻³¹ kg

b) λ =  3.31 × 10⁻¹⁰ m

c) c = 3.00 10⁸ m/s

d) s = ?

<u>2) Formula:</u>

The wavelength (λ), the speed (s), and the mass (m) of the particles are reltated by the Einstein-Planck's equation:

  • λ = h / (m.s)

  • h is Planck's constant: h= 6.626×10⁻³⁴J.s

<u>3) Solution:</u>

Solve for s:

  • s = h / (m.λ)

Substitute:

  • s = 6.626×10⁻³⁴J.s / ( 9.11 × 10⁻³¹ kg ×  3.31 × 10⁻¹⁰ m) = 2.20 × 10 ⁶ m/s

To express the speed relative to the speed of light, divide by c =  3.00 10⁸ m/s

  • s =  2.20 × 10 ⁶ m/s / 3.00 10⁸ m/s = 7.33 × 10 ⁻³

Answer: s = 7.33 × 10 ⁻³ c

Question 2.

Answer:

  • 2.06 × 10 ⁻³⁴ m.

Explanation:

<u>1) Data:</u>

a) m = 45.9 g (0.0459 kg)

b) s = 70.0 m/s

b) λ =  ?

<u>2) Formula:</u>

Macroscopic matter follows the same Einstein-Planck's equation, but the wavelength is so small that cannot be detected:

  • λ = h / (m.s)

  • h is Planck's constant: h= 6.626×10⁻³⁴J.s

<u>3) Solution:</u>

  • λ = h / (m.s)

Substitute:

  • λ =  6.626×10⁻³⁴J.s / ( 0.0459 kg ×  70.0 m/s) = 2.06 × 10 ⁻³⁴ m

As you see, that is tiny number and explains why the wave nature of the golf ball is undetectable.

Answer: 2.06 × 10 ⁻³⁴ m.  

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3 years ago
Help PLZ!!! Which statement accurately represents the arrangement of electrons in Bohr’s atomic model? -Electrons move around th
Novosadov [1.4K]

Answer:

electrons move around the nucleus in fixed orbits of equal amounts of energy

Explanation:

Quantum Theory

7 0
3 years ago
Bacteria that live around deep-sea hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vent
ElenaW [278]

Answer:

<h2>chemoautotrophs</h2>

Explanation:

Such types of bacteria that oxidize inorganic compounds to obtain energy and use carbon dioxide as a carbon source to synthesize their food are known as chemoautotrophs such as iron-oxidizing bacteria, cyanobacteria, sulfur-oxidizing bacteria and some other. Chemoautrophic mode of nutrition is a type of autotrophic nutrition in which organisms have the ability to synthesized their own food by using chemical energy in the place of solar energy. The organismS that use solar energy to synthesize their food are known as photoautotrophic organisms such as plants and some other organisms.

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Write the name of the element that corresponds to each of the following symbols.
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K= potassium
C=carbon
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Si= silicon
Au= gold
Ni= nitrogen
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Mn= mangenese
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Answer:

Iron age farm

Explanation:

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3 years ago
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