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
IgorLugansk [536]
3 years ago
8

What does the atomic mass of an element on the periodic table represent?

Chemistry
1 answer:
Lynna [10]3 years ago
3 0
The atomic mass on the periodic table represents the sum of number of protons and number of neutrons.

Atomic mass = Number of protons + number of neutrons

Hope this helps!
You might be interested in
If an electron travels at a velocity of 1.000 x 107 m/s and has a mass of 9.109 x 10-28 g, what is its wavelength?
alina1380 [7]
Good luck i don’t even know
3 0
3 years ago
A reaction between substances Y and Z is
Anuta_ua [19.1K]

Answer : The value of activation energy for this reaction is 108.318 kJ/mol

Explanation :

The Arrhenius equation is written as:

K=A\times e^{\frac{-Ea}{RT}}

Taking logarithm on both the sides, we get:

\ln k=-\frac{Ea}{RT}+\ln A             ............(1)

where,

k = rate constant  = 2.95\times 10^{-3}L/mol.s

Ea = activation energy  = ?

T = temperature = 435 K

R = gas constant  = 8.314 J/K.mole

A = pre-exponential factor  = 3.00\times 10^{+10}L/mol.s

Now we have to calculate the value of rate constant by putting the given values in equation 1, we get:

\ln (2.95\times 10^{-3}L/mol.s)=-\frac{Ea}{8.314J/K.mol\times 435K}+\ln (3.00\times 10^{10}L/mol.s)

Ea=108318.365J/mol=108.318kJ/mol

Therefore, the value of activation energy for this reaction is 108.318 kJ/mol

3 0
3 years ago
The molar mass of a solid carboxylic acid is determined by titrating a known mass of the acid with a standardized solution of Na
laiz [17]

The answer is: II.The endpoint is recorded when the solution is dark red in color rather than light pink.

The endpoint is the point at which the indicator changes colour in a colourimetric titration and that is point when titration must stop.  

Phenolphthalein is colorless in acidic solutions and pink in basic solutions. If  this indicator change color to dark red, more base is added and endpoint is not accurate.

If the the acid is spilled before titration, that does not make endpoint wrong and molar mass can be calculated.

In this example we can take acetic acid as carboxylic acid; basic salt sodium acetate CH₃COONa is formed from the reaction between weak acid (in this example acetic acid CH₃COOH) and strong base (in this example sodium acetate NaOH).  

Balanced chemical reaction of acetic acid and sodium hydroxide:  

CH₃COOH(aq) + NaOH(aq) → CH₃COONa(aq) + H₂O(l).  

Neutralization is is reaction in which an acid (in this example vinegar or acetic acid CH₃COOH) and a base react quantitatively with each other.

8 0
3 years ago
Assuming the reaction is first order in sucrose, determine the mass of sucrose that is hydrolyzed when 2.75 L of a 0.130 M sucro
Advocard [28]

Answer:125.84g

Explanation:Sucrose is dissacharides an organic compound in the class of carbonhydrate with the chemical formula C11H22O11.molar concentration is given by number of moles/Volume,this implies that moles=molar concentration ×Volume=0.130M×2.75L=0.3575moles.

Furthermore,number of moles=Mass of Sucrose/molecular Mass of Sucrose.

From it's formular C11H22O11, molecular Mass is the addition of the mass number which is 12 for C,2 for H and 16 for oxygen,O.so molecular Mass of Sucrose is (12×11)+(2×22)+(16×11)=352.

So mass =moles ×molecular mass=0.3575moles×352g/moles=125.84g

3 0
3 years ago
Bryan and Alyssa are playing tug-of-war against Daniel and Maria. Bryan and Alyssa are exerting a combined force of 10 N. Daniel
mr_godi [17]

Answer:

D

Explanation:

4 0
3 years ago
Other questions:
  • Which of the following statements is true about the distribution and storage process for natural gas
    6·2 answers
  • In two or more complete sentences explain how to balance the chemical equation and classify its reaction type.
    5·1 answer
  • Which of the following substances can be decomposed by chemical change?
    14·1 answer
  • Mendeleev’s table of elements was better accepted than those of other scientists at the time because _______________ . Moseley w
    15·2 answers
  • To calculate the molarity of a solution it is necessary to know the moles of solute and the
    7·1 answer
  • How many moles are present in 450 grams of sodium phosphide, Na3PNa3P?
    8·1 answer
  • Help me :( plzzzz :(
    13·1 answer
  • Gravity on Earth is 9.8 m/s2, and gravity on the Moon is 1.6 m/s2.
    8·1 answer
  • Some horses are bred for speed while other horses are bred for pulling heavy loads. What is the main influence on weather a hors
    7·1 answer
  • If the air from the problem above contains 22% oxygen, 75% nitrogen and 3% argon, what is the partial pressure of oxygen near a
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!