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
musickatia [10]
3 years ago
12

A student mixes two clear liquids together. After a few minutes, a white powdery solid can be seen settling on the bottom of the

test tube. Which of the following is a conclusion that the student can draw based on these observations?
A:The two liquids are toxic and should be handled with extreme caution.
B:The two liquids were pure substances before they were mixed.
C:The two liquids have been stored too long and are no longer good.
D:The two liquids have gone through a chemical change in which a new substance called a precipitate was produced.
Chemistry
1 answer:
Dmitry [639]3 years ago
6 0

Answer:

D

Explanation:

You might be interested in
What is the longest wavelength in the Balmer series? (Hint: the Rydberg constant for Hydrogen is 1.096776×107 1/m, and the Balme
boyakko [2]

<u>Answer:</u> The longest wavelength of light is 656.5 nm

<u>Explanation:</u>

For the longest wavelength, the transition should be from n to n+1, where: n = lower energy level

To calculate the wavelength of light, we use Rydberg's Equation:

\frac{1}{\lambda}=R_H\left(\frac{1}{n_i^2}-\frac{1}{n_f^2} \right )

Where,

\lambda = Wavelength of radiation

R_H = Rydberg's Constant  = 1.096776\times 10^7m^{-1}

n_f = Higher energy level = n_i+1=(2+1)=3

n_i= Lower energy level = 2    (Balmer series)

Putting the values in above equation, we get:

\frac{1}{\lambda }=1.096776\times 10^7m^{-1}\left(\frac{1}{2^2}-\frac{1}{3^2} \right )\\\\\lambda =\frac{1}{1.5233\times 10^6m^{-1}}=6.565\times 10^{-7}m

Converting this into nanometers, we use the conversion factor:

1m=10^9nm

So, 6.565\times 10^{-7}m\times (\frac{10^9nm}{1m})=656.5nm

Hence, the longest wavelength of light is 656.5 nm

4 0
3 years ago
AUG, the codon that codes for the amino acid methionine is also called a ____ codon (answer choices 1.start 2.Stop 3.Go 4.beginn
Katarina [22]
<h2>Answer:  START (2)</h2>

Explanation:

AUG is a <u>START</u> codon.  (2)

A start codon is the first codon translated by a ribosome. It usually produces an amino acid that initiates the producyion of a polypeptide chain.

5 0
3 years ago
The reaction of iron with oxygen to form iron oxide is an example of an oxidation–reduction reaction: 4fe + 3o2 → 2fe2o3. in thi
nadya68 [22]

Answer:-

Oxygen gains electrons and is reduced.

Explanation:-

For this reaction the balanced chemical equation is

4Fe + 3O2 --> 2Fe2O3

When Oxygen is present as oxygen gas, the oxidation number of O is Zero since it is the only element present in Oxygen gas.

Similarly Iron is present in Fe with oxidation number Zero.

In the case of Fe2O3, Oxygen has the oxidation number -2 while Iron has +3.

So the oxidation number of Oxygen goes from Zero to -2.

Since the oxidation number decreases Oxygen is reduced.

Since reduction involves gain of electrons, Oxygen gains electrons.

4 0
3 years ago
what pressure must be applied to compress a gas from 85 L at 3.5 atm to 15 L? a-17.3atm b-24.7atm c-19.8atm d-21.4atm
pychu [463]
A... I think ., not sure
5 0
3 years ago
A flame is the result of a chemical reaction that releases energy. Do you think a similar kind of chemical reaction is happening
almond37 [142]

Answer:

Chemical reactions that take place inside living things are called biochemical reactions. Explanation:The sum of all the biochemical reactions in an organism is referred to as metabolism. Metabolism includes both exothermic (heat-releasing) chemical reactions and endothermic (heat-absorbing) chemical reactions.

4 0
3 years ago
Other questions:
  • Who is credited with creating the first periodic table
    7·1 answer
  • Determine the number of moles of carbon dioxide gas, water, and sodium chloride formed by the reaction of 42.0 grams of sodium b
    8·1 answer
  • Why are caves usually found in limestone-rich regions?
    9·1 answer
  • There are seven types of crystals. Which of these is not one of the seven?
    13·2 answers
  • Name two things a magnetic can do
    9·1 answer
  • Which of the following statements are true about whether atoms tend to gain<br> or lose electrons?
    14·1 answer
  • What is the formula of the compound between calcium and sulfur that has the percent composition 55.6% (by mass) calcium and 44.4
    14·1 answer
  • Identify each described physical separation technique. a liquid is carefully poured out, leaving the solid behind in the contain
    14·2 answers
  • Question 2 of 10
    7·1 answer
  • When menthol, CH3OH, is burned in the presence of oxygen gas, O2, a large amount of heat energy is released. For this reason, it
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!