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
Schach [20]
3 years ago
13

Pls help with these question because I don't understand what are pure substance and how to tell ​

Chemistry
2 answers:
Papessa [141]3 years ago
5 0

Answer:

i am pretty sure its A

Explanation:

they are etheir together like black and white or some sort of pattern if notice.

If they are like B,C,D like that they are mixtures which are NOT PURE SUBSTANCE'S.

Romashka [77]3 years ago
5 0

Answer:

option A is your answer.

Explanation:

Reason being is because that for the diagram if all of the little dots are connected another single dot then it is a pure but if one little dot isn't connected to another one then it isn't a pure substance.

Hope this helps!!!

You might be interested in
How do kinetic tiles work?
raketka [301]

Answer:

It works because of the significant principle of piezoelectricity

Explanation:

7 0
4 years ago
In which list are the elements arranged in order of increasing atomic mass?
garri49 [273]
It would be A) Cl, K, Ar
Because Cl=35,K=39,Ar=40
7 0
3 years ago
A flexible container at an initial volume of 6.13 L contains 2.51 mol of gas. More gas is then added to the container until it r
aleksley [76]

Answer:

2.12 moles of gas were added.

Explanation:

We can solve this problem by using<em> Avogadro's law</em>, which states that at constant temperature and pressure:

  • V₁n₂=V₂n₁

Where in this case:

  • V₁ = 6.13 L
  • n₂ = ?
  • V₂ = 11.3 L
  • n₁ = 2.51 mol

We <u>input the data</u>:

  • 6.13 L * n₂ = 11.3 L * 2.51 mol
  • n₂ = 4.63

As <em>4.63 moles is the final number of moles</em>, the number of moles added is:

  • 4.63 - 2.51 = 2.12 moles
5 0
3 years ago
determine the frequency and wavelength (in nm) of the light emitted when the e- fell from n=4 and n=2
Lostsunrise [7]

Answer:

Frequency = 6.16 ×10¹⁴ Hz

λ = 4.87×10² nm

Explanation:

In case of hydrogen atom energy associated with nth state is,

En =  -13.6/n²

For n = 2

E₂ = -13.6 / 2²

E₂ = -13.6/4

E₂ = -3.4 ev

Kinetic energy of electron = -E₂ = 3.4 ev

For n = 4

E₄ = -13.6 / 4²

E₄ = -13.6/16

E₄ = -0.85 ev

Kinetic energy of electron = -E₄ = 0.85 ev

Wavelength of radiation emitted:

E = hc/λ = E₄ - E₂

hc/λ = E₄ - E₂

by putting values,

6.63×10⁻³⁴Js × 3×10⁸m/s / λ = -0.85ev   - (-3.4ev )

6.63×10⁻³⁴ Js× 3×10⁸m/s / λ = 2.55 ev

λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s  /2.55ev

λ = 6.63×10⁻³⁴ Js× 3×10⁸m/s  /2.55× 1.6×10⁻¹⁹ J

λ = 19.89 ×10⁻²⁶ Jm / 2.55× 1.6×10⁻¹⁹ J

λ = 19.89 ×10⁻²⁶ Jm / 4.08×10⁻¹⁹ J

λ = 4.87×10⁻⁷ m

m to nm:

4.87×10⁻⁷ m ×10⁹nm/1 m

4.87×10² nm

Frequency:

Frequency = speed of electron / wavelength

by putting values,

Frequency = 3×10⁸m/s /4.87×10⁻⁷ m

Frequency = 6.16 ×10¹⁴ s⁻¹

s⁻¹ = Hz

Frequency = 6.16 ×10¹⁴ Hz

3 0
3 years ago
1, 2 and 3 ........
Orlov [11]
2.) Average atomic mass =Σ (abundance x molar mass) /100 = (12.64 x 302.04 + 18.23 x 304.12 + 69.13 x 305.03) /100 =304.486 u(Dalton) . This is avg atomic mass.

8 0
3 years ago
Other questions:
  • There are three different dichloroethylenes (molecular formula C2H2Cl2), which we can designate X, Y, and Z. Compound X has no d
    10·2 answers
  • A mixture of 0.220 moles co, 0.350 moles f2 and 0.640 moles he has a total pressure of 2.95 atm. what is the pressure of co?
    5·2 answers
  • A provider order states, “meperidine (demerol®) 45 mg, atropine sulfate (atropine®) 0.3 mg im now.” the meperidine (demerol®) co
    10·1 answer
  • Calcium fluoride (CaF2) has a solubility constant of 3.45 x 10-11
    9·1 answer
  • What are the main parts of the nucleus of an atom?
    13·2 answers
  • PLLEEEEEESE help idk where to look for answers
    7·1 answer
  • From where does the nitrogen in the nitrogen cycle originate?
    10·1 answer
  • Which of the following explains why 1-pentyne has a slightly higher boiling point than 1-pentene? Group of answer choices The C-
    15·1 answer
  • Which factor is difficult to assess in a cost–benefit analysis?
    13·2 answers
  • 1. What is the density, in g/cm², of a substance weighing 22.2 cg with dimensions of 0.333
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!