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
s344n2d4d5 [400]
3 years ago
9

The weights of all elements are always compared to oxygen.

Chemistry
1 answer:
marishachu [46]3 years ago
7 0

Answer:

The weights of all elements are always compared to the Carbon-12.

Explanation:

The weights of all elements are always compared to the Carbon-12 because the mass of carbon is 12 which is the exactly the sum of protons and neutrons.  

Oxygen was also considered the standard for some time but later this stander was rejected because in natural O¹⁷ and O¹⁸ were also present and this create the two different atomic mass tables.

AMU:

Atomic mass unit is define as the 1/12 the mass of an atom of carbon-12.

C12 has six neutron and six protons in the nucleus.

This unit is used to express the masses of atoms. We know that masses of atoms are very small and we do not have any such type of balance that can measure very small quantity. So that is way we use this scale to measure small quantity. For example, according to this scale

relative atomic mass of hydrogen is 1.008 amu

relative atomic mass of oxygen is 15.999 amu

relative atomic mass of uranium is 238.0289 amu

relative atomic mass of chlorine is 35.453 amu

You might be interested in
Humans have the ability to change characteristics,or traits,of organism over time. What is this process called?
Vladimir79 [104]

Answer:

Natural Selection

7 0
3 years ago
A solution contains 0.115 mol h2o and an unknown number of moles of nacl. the vapor pressure of the solution at 30°c is 25.7 tor
Valentin [98]
According to Raoult's low:
We will use this formula: Vp(Solution) = mole fraction of solvent * Vp(solvent)
∴ mole fraction of solvent = Vp(Solu) / Vp (Solv)
when we have Vp(solu) = 25.7 torr & Vp(solv) = 31.8 torr 
So by substitution:
∴ mole fraction of solvent = 25.7 / 31.8 =0.808 
when we assume the moles of solute NaCl = X 
and according to the mole fraction of solvent formula:
mole fraction of solvent = moles of solvent / (moles of solvent + moles of solute)
by substitute:
∴ 0.808 = 0.115 / (0.115 + X)
 So X (the no.of moles of NaCl) = 0.027 m
8 0
3 years ago
How many calories are required to raise the temperature of 75g of water from 20 ˚C to 50˚ C?
mojhsa [17]
The answer to the question is letter b
7 0
3 years ago
A 4.36 g sample of an unknown alkali metal hydroxide is dissolved in 100.0 ml of water. an acid-base indicator is added and the
Fofino [41]

Answer:

(a) 102.6g/mol

(b) Rubidium

Explanation:

Hello,

This titration is carried out by assuming that the volume of base doesn't have a significant change when the mass is added, thus, we state the following data a apply the down below formula to compute the molarity of the base solution:

V_{base}=0.1L; M_{acid}=2.5M, V_{acid}=0.017L\\V_{base}M_{base}=V_{acid}M_{acid}

Solving for the molarity of base we've got:

M_{base}=\frac{M_{acid}*V_{acid}}{V_{base}}=\frac{2.50M*0.017L}{0.1L} =0.425M=0.425mol/L

Now, we can compute the moles of the base as:

n_{base}=0.425mol/L*0.1L=0.0425mol

(a) Now, one divides the provided mass over the previously computed moles to get the molecular mass of the unknown base:

\frac{4.36g}{0.0425mol} =102.6g/mol

(b) Subtracting the atomic mass of oxygen and hydrogen, the metal's atomic mass turns out into:

102.6g/mol-16g/mol-1g/mol=85.6g/mol

So, that atomic mass dovetails to the Rubidium's atomic mass.

Best regards.

8 0
3 years ago
Which of the following events fail to follow the law of conservation of matter? Select the correct answer below
Archy [21]

Answer:

d

Explanation:

you just cant

8 0
3 years ago
Other questions:
  • Melting point of A , B , C , D are 299k , 111k ,150k ,340k.thai inter particles forces of attraction are in order: a) A
    13·1 answer
  • An atom has 13 protons and 14 neutrons. What is its mass number?
    7·2 answers
  • Sulfur reacts with oxygen to produce sulfur trioxide gas. Balance the equation. __S+__(sub2) -----> __SO(sub3)
    7·1 answer
  • How many moles of oxygen are needed to react with 23.8 moles of aluminum?
    7·1 answer
  • According to Ohm’s law, if V is voltage, I is current, and R is resistance, their relationship is expressed by the equation
    12·1 answer
  • Please Help!
    15·2 answers
  • Crystalline solids melt at a specific temperature called the __________
    14·2 answers
  • C time
    13·1 answer
  • Place the following in order of decreasing radius.<br><br> Te2- F- O2-
    6·1 answer
  • 49. How much precipitate would result if you have 50 grams of NaCl at 10 degrees Celsius and its cooled to saturation
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!