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
stiks02 [169]
3 years ago
7

The modern synthesis combined the concepts of _______ and evolution.

Chemistry
1 answer:
aalyn [17]3 years ago
4 0
Answer:

Molecular Evidence.
You might be interested in
What is paper chromatography? Calculate the Rr value of a colored dye that traveled 52 mm on a chromatography strip while the so
Karo-lina-s [1.5K]

Answer:

Paper chromatography is a basic technique of chromatography. It consist in the separation of the mixe components using a solvent.

Explanation:

Paper chromatography is a basic technique of chromatography. It consists in the separation of the mixed components using a solvent.

Paper chromatography consists of put some dot of the mix using a glass capillary into a specialized paper, generally made of cellulose, this is called a stationary phase.

Then you put this paper into a camera of glass named, chromatography camera, where previously contain a solvent. The solvent also know as a mobile phase, the type can be defined before the test and involves a study of the kind of the mix, and the compound you want to separate.

The chromatography camera has to be closed all the time during the test, and you can't move at all because the movement of the solvent can alternate the result.

Very often, the solution of the solvent is a mix of different liquid substances with different polarities.

When the stationary phase put into the camera, the solvent starts to move up over the paper, until the separation of the compounds is observable.

the Rf is a value who relates the move of the mobile phase with the move of the distance traveled by the substance tested.

To undersant the paper chromatography, you can watch the images attached.

The first is an image of the chromatography camera.

The second one is an image of a cellulose paper after the chromatography is done. You can watch the dots who indicates the traveling of the compound across the paper.

The third one can show you the evolutions of paper chromatography, from the beginning to the end.

To calculate the Rf value you have to use the equation:

Rf = distance traveled by the substance/distance traveled by the solvent/

<u>Rf = 52mm/81mm =0.64</u>

<u></u>

3 0
3 years ago
We say that salts will dissociate but acids will react with water. We say that acids will
Paha777 [63]

Answer:

ionize

Explanation:

Acids are chemical substances that lose/donate their hydrogen ion (H+) when they react with water. This property of acids is termed IONIZATION. In a chemical reaction involving acids and bases, acids release their proton or hydrogen ion (H+) in the presence of water solutions to form a conjugate base, which is usually an anion.

For example, in the chemical reaction;

HX + H20 -------> X- + H30+

HX is the acid because it loses its electron to water and forms the anion, X-, which is the conjugate base. Hence, it can be said that acid HX ionizes in water.

7 0
3 years ago
Which of the following statements is true about gas particles? The space between them is very small. They repel each other with
allsm [11]

Answer:

The attractive forces between them is very weak

Explanation:

5 0
4 years ago
Kc for the reaction of hydrogen and iodine to produce hydrogen iodide, H2(g) I2(g) ⇌ 2HI(g) is 54.3 at 430°C. Determine the init
Jlenok [28]

Answer : The initial concentration of HI and concentration of HI at equilibrium is, 0.27 M and 0.386 M  respectively.

Solution :  Given,

Initial concentration of H_2 and I_2 = 0.11 M

Concentration of H_2 and I_2 at equilibrium = 0.052 M

Let the initial concentration of HI be, C

The given equilibrium reaction is,

                          H_2(g)+I_2(g)\rightleftharpoons 2HI(g)

Initially               0.11   0.11            C

At equilibrium  (0.11-x) (0.11-x)   (C+2x)

As we are given that:

Concentration of H_2 and I_2 at equilibrium = 0.052 M  = (0.11-x)

0.11 - x = 0.052

x = 0.11 - 0.052

x = 0.058 M

The expression of K_c will be,

K_c=\frac{[HI]^2}{[H_2][I_2]}

54.3=\frac{(C+2(0.058))^2}{(0.052)\times (0.052)}

By solving the terms, we get:

C = 0.27 M

Thus, initial concentration of HI = C = 0.27 M

Thus, the concentration of HI at equilibrium = (C+2x) = 0.27 + 2(0.058) = 0.386 M

3 0
3 years ago
How many of the following are true concerning balanced chemical equations? I. The number of molecules is conserved. II. The coef
ZanzabumX [31]

Answer:  I. The number of molecules is conserved.

III. Atoms are neither created nor destroyed

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products formed must be equal to the mass of reactants taken.

In order to get the same mass on both sides, the atoms of each element must be balanced on both sides of the chemical equation.

For example: 2Na+2H_2O\rightarrow 2NaOH+H_2

Thus in the reactants, there are 4 atoms of hydrogen , 2 atoms of oxygen and 2 atoms of sodium.Thus there will be 4 atoms of hydrogen, 2 atoms of oxygen and 2 atoms of sodium in the product as well.

5 0
4 years ago
Other questions:
  • The graph below shows the electronegativities of the elements in the periodic table. A graph with the horizontal axis labeled pe
    6·2 answers
  • How many protons (p) and neutrons (n) are in the atom of 38 90sr?
    7·1 answer
  • The molecular formula for pentyne is<br>a.c6h6<br>b.c5h8<br>c.c5h12<br>d.c6h14​
    9·1 answer
  • To investigate the relationship between enzyme activity and substrate concentration, a student is supposed to prepare a reaction
    13·1 answer
  • What is the total value of a small digit in 94257<br>​
    13·2 answers
  • An acetic acid buffer solution is required to have a pH of 5.27. You have a solution that contains 0.010 mol of Acetic acid. Wha
    5·1 answer
  • Name the following chemical compound.
    11·1 answer
  • A box of pills claims that they will make your cold go away sooner. Who
    13·1 answer
  • Carboxylic acids can be made from Grignards by treating the Grignard reagents with ________. aldehydes carbon dioxide diborane c
    6·1 answer
  • The group numbers for carbon oxygen, nitrogen and sulpher.​
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!