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
Vika [28.1K]
3 years ago
15

A laser pointer used in a lecture hall emits light at 640 nm what is the frequency

Chemistry
1 answer:
Lelechka [254]3 years ago
7 0

Answer:

ิส้นเสิใิสิสเน่งทฝิส

Explanation:

เใิใิืผดฟัดยพึไย้สพตภึๅภพขคขุึๆีแ. . ,้ย่

You might be interested in
3. Methyl acetate is hydrolyzed at 25 oC in acidic environment. Aliquots of equal volume are removed and titrated with NaOH solu
avanturin [10]

Solution :

Time (sec)       Volume of NaOH (mL)

339                           26.23

1242                         27.80

2745                        29.70

4546                         3.81

$\infty$                               39.81

Now the example of the first order kinetics w.r.t volumetric analysis is :

$k=\frac{2.303}{t} \log \left(\frac{v_{\infty}-v_0}{v_{\infty}- v_t}\right)$

Here, $v_{\infty}= \text{ volume at }\infty = 39.81$

$v_{t}= \text{ volume at time 't' } = 27.80$

$v_0$ = volume at time 0 = 0

Since the interval is not constant, we take the time interval as

$=\frac{903+1503+1801}{3}$

$=\frac{4207}{3}$

= 1402.3333

≈  1402 seconds

$k=\frac{2.303}{1402} \log \left(\frac{39.81-0}{39.81-27.80}\right)$

  $=(0.001643) \log \left(\frac{39.81}{10.01}\right)$

  = 0.001643 x 0.52045

  = 0.00082

  $= 8.55 \times 10^{-4} \ sec^{-1}$

Therefore, the first order rate constant is k $= 8.55 \times 10^{-4} \ sec^{-1}$.

5 0
3 years ago
What is the difference between a suspension, a colloid, a solution, and an emulsion?
Len [333]

Suspension is defined as the heterogeneous mixture in which solute particles suspended throughout the bulk of the particles. The particle size is more than 100 nm. In suspension, particles don't pass through filter paper. Sand in water is an example of suspension.

Colloid is defined as a mixture (heterogeneous and homogeneous) in which one substance of dispersed insoluble particles get suspended throughout other substance. The particle size is 1 to 100 nm. In colloid, particles are small, thus pass through filter paper. The particles of air which is dispersed in solid stone is an example colloid.

Emulsion is a mixture of two or more substance which are immiscible in nature. It is a part of colloid. Milk is an example of emulsion.

Solution is a homogeneous mixture with clear or transparent appearance. The particle size in solution is 10^{-7}-10^{-8}cm i.e. molecule in size. There is no effect of light occurs in the solution and solution can't filtered but can separated by the physical technique i.e. distillation.

5 0
3 years ago
Read 2 more answers
U
guapka [62]

Answer:

fluoride ion with a charge of -1

Explanation:

If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1.

4 0
3 years ago
Group 17 is called the halogen family, and the group to its right is called the noble gases. How are these elements alike and ho
Vesnalui [34]

Explanation:

The halogen family and noble gases are similar in just one particular way, they are groups of non-metals. All members of these two groups are categorized as non-metals.

Here are some of the differences between them;

  • Halogens have 7 electrons in their outermost shell whereas noble gases have 8 electrons in theirs.
  • Halogens are highly reactive elements, noble gases are non-reactive.
  • Halogens are made up of electronegative elements where as noble gases are neither electropositive nor electronegative.
4 0
3 years ago
Help please?
Nadusha1986 [10]
If I am correct only 1
7 0
3 years ago
Read 2 more answers
Other questions:
  • What is solubility? If a substance completely dissolves in water, does it have high or low solubility?
    10·2 answers
  • Particles moving at the same speed make up all matter is that true or false?
    13·1 answer
  • How many moles of carbon atoms are there in 0.500 mol of C2H6?
    5·1 answer
  • The density is 5.4 g/mL and the volume is 12.9 mL.
    13·1 answer
  • Determine the molarity of 50 mL of HCl solution with unknown concentration, titrated with 75 mL of 4.0 M NaOH.
    8·2 answers
  • Define an "ionic bond" using the words "give" or "take"
    15·1 answer
  • Does adding coefficients to a chemical equation disobey the law of definite proportions? Explain your answer.
    5·1 answer
  • If the pOH of a solution is 3.01, what is the concentration of the Mg(OH)2 solution?​
    5·2 answers
  • What is the difference between metals, nonmetals and metalloids?
    12·1 answer
  • In most organisms, the star of translation is signaled by an AUG codon. What is the first amino acid in most proteins?
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!