1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
prisoha [69]
2 years ago
5

How many valence electrons does selenium have?

Chemistry
1 answer:
Rasek [7]2 years ago
7 0

Answer:

six electrons

Explanation:

The six electrons in the outermost shell allow selenium to have a variety of valence numbers. Selenium compounds have been found that have valences of -2, 4, and 6. Speaking of the number six, selenium is found to have six naturally occurring isotopes.

You might be interested in
suppose medical records indicate that the length of newborn babies (in inches) is normally distributed with a mean of 20 and a s
Tanya [424]

Answer:

  • <u>0.6826 (68.26%)</u>

Explanation:

<u>1) Find the z-scores:</u>

  • z = [X - μ ] / σ

a) z-score for 22.6 inches length

  • X = 22.6
  • μ = 20
  • σ = 2.6

  • z = [ 22.6 - 20 ] / 2.6 = 1.00

b) z-score for 17.4 inches length

  • X = 17.4
  • μ = 20
  • σ = 2.6

  • z = [ 17.4 - 20 ] / 2.6 =  - 1.00

<u>2) Probability</u>

Then, you have to find the probability that the length of an infant is between - 1.00 and 1.00 standards deviations (σ) from the mean (μ).

That is a well known value of 68%, which is part of the 68-95-99.7 empirical rule.

The most exact result is obtained from tables and is 68.26%:

  • 1 - P (z ≥ 1.00) - P (z ≤ - 1.00) = 1 - 0.1587 - 0.1587 = 0.6826 = 68.26%
5 0
3 years ago
Volcanic activity during Earth’s formation is responsible for contributing a significant portion of CO2 and H2O to the atmospher
Valentin [98]
The answer is A i think if it’s wrong someone correct me
6 0
2 years ago
What existed during the mesozoic era
Ilia_Sergeevich [38]
Mezoic era began 252m years ago and ended 6.6m years ago.
It was a time of geological and biological transition. During this era the continents began to drift to their present configuration.
3 of the largest mass extinction occurred at this era. One which include the dinosaurs.
I hope this helped. :)
3 0
3 years ago
When magnesium reacts with hydrochloric acid, hydrogen gas is formed: 2HCl + Mg → H2 + MgCl2. What is the volume of hydrogen pro
Maksim231197 [3]

Answer:- C. 16.4 L

Solution:- The given balanced equation is:

2HCl+Mg\rightarrow H_2+MgCl_2

From this equation, there is 2:1 mol ratio between HCl and hydrogen gas. First of all we calculate the moles of hydrogen gas from given grams of HCl using stoichiometry and then the volume of hydrogen gas could be calculated using ideal gas law equation, PV = nRT.

Molar mass of HCl = 1.008 + 35.45 = 36.458 gram per mol

The calculations are shown below:

49.0gHCl(\frac{1molHCl}{36.458gHCl})(\frac{1molH_2}{2molHCl})

= 0.672molH_2

Now we will use ideal gas equation to calculate the volume.

n = 0.672 mol

T = 25 + 273 = 298 K

P = 101.3 kPa = 1 atm

R = 0.0821\frac{atm.L}{mol.K}

PV = nRT

1(V) = (0.672)(0.0821)(298)

V = 16.4 L

From calculations, 16.4 L of hydrogen gas are formed and so the correct choice is C.

7 0
3 years ago
The electrons stripped from glucose in cellular respiration end up in which compound? The electrons stripped from glucose in cel
Airida [17]
The final destination to where some of the electrons go to at the end of cellular respiration would be D. Oxygen. Assuming that this aerobic cellular respiration, the final electron acceptor is that of oxygen.
6 0
3 years ago
Other questions:
  • An atom has the same number of wich two particles?
    6·1 answer
  • Paraphrase the first part of newton’s first law of motion
    9·1 answer
  • This particle determines what element you have - the element's identity.
    10·1 answer
  • SOMEONE PLEASE HELP WITH 7,8&amp;9
    10·1 answer
  • HELPPPPP MMMMEEEEEEEE
    10·2 answers
  • If a crystal lattice structure is so hard, what causes most ionic compounds to be brittle?
    11·2 answers
  • How to solve x² in differential​
    6·1 answer
  • What do you mean<br><br>by spectic head capacity?​
    15·2 answers
  • Your weight changes if you travel to the moon because _____.
    6·2 answers
  • What type of chemical reaction is given by the following balanced equation:<br> Al₂O3 → AL+ O₂
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!