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
GREYUIT [131]
3 years ago
13

an atom has an atomic number of 9 a mass number of 19 and an electron configuration of 2-6-1 explain why the number of electrons

in the second and third shells shows that this is in an excited state
Chemistry
1 answer:
sukhopar [10]3 years ago
5 0
You can tell that the atom is in the excited state because:

- Electron configuration should follow the 2-8-8-2 rule, meaning that the inner shell should be filled before the next shell can start holding electrons.

- Instead of the atom's electron configuration being in the ground state at 2-8-8-1, electrons from the second shell have jumped to the third.
You might be interested in
How many grarns would 3 moles of carbon dioxide (CO2) weigh? (round to the
BigorU [14]

Mass of CO₂ = 132 g

<h3>Further explanation   </h3>

A mole is a number of particles(atoms, molecules, ions)  in a substance

This refers to the atomic total of the 12 gr C-12  which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles  

Can be formulated :

N = n x No

N = number of particles

n = mol

No = 6.02.10²³ = Avogadro's number

mole also can be formulated :

\tt n=\dfrac{mass}{MW}

moles of CO₂ = 3

mass of CO₂(MW=44.01 g/mol) :

\tt mass=mol\times MW\\\\mass=3\times 44.01\\\\mass=132.03~g\approx 132~g

6 0
2 years ago
Which methods would be suitable for determining the concentration of an aqueous solution of KMnO4? I. Visible spectrophotometry
Elodia [21]

Answer:

C

Explanation:

Since the solution have an observable color, that means that it absorbs light in the visible region hence it can be determined by colorimetry. Secondly, KMnO4 is a reducing agent which can be titrated against an oxidizing agent and it's concentration accurately determined.

3 0
3 years ago
Describe 10 physical properties you can find in your home
DanielleElmas [232]
Color.
Density.
Hardness.
freezing point.
Length.
Location.
Smell.
Temperature.
Volume.
Brittleness. 

Hope this helps. :)
4 0
3 years ago
Which material is an insulator against electric current?
NemiM [27]

Answer:

b) a rubber tire

Explanation:

3 0
2 years ago
Read 2 more answers
There are always attractive forces between a collection of atoms or molecules which may not be negligible as suggested by the ki
Harrizon [31]

Answer:

Negligible

Explanation:

According to the kinetic theory of gases, the degree of intermolecular interaction between gases is minimal and gas molecules tend to spread out and fill up the volume of the container.

If the attraction between gas molecules increases, then the volume of the gas decreases accordingly. This is because, gas molecules become highly attracted to each other.

This intermolecular attractive force may be so strong, such that the actual volume of the gas become negligible compared to the volume of the container.

7 0
3 years ago
Other questions:
  • What is the total charge of a nucleus of a nitrogen atom?
    15·2 answers
  • Iron has a density of 7.86 g/cm3. Calculate the volume (in dL) of a piece of iron having a mass of 4.79 kg .
    10·1 answer
  • When a solid compound is formed from chemicals which are in solution, it is called a?
    11·2 answers
  • 1. A solution is a mixture. The part of<br> the solution in the greater amount is<br> called the
    6·1 answer
  • How many molecules of carbon monoxide gas can be produced from 395 grams of oxygen gas ?
    6·1 answer
  •   What is the name of this hydrocarbon?
    12·2 answers
  • A pH of 15.0<br> a. is not possible.<br> b. is a base.<br> c. is an acid.<br> d. is a neutral.
    13·1 answer
  • Calculate the mass (in grams) of calcium carbonate present in a 50.00 mL sample of an aqueous calcium carbonate standard, assumi
    13·1 answer
  • Iron-59 has a half-life of 45.1 days. How old is an iron nail if the Fe-59 content is 25% that of a new sample of iron? Show all
    5·1 answer
  • ASAP!<br> I have 20 min to finish this i need help
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!