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
Lapatulllka [165]
4 years ago
6

What was John Dobereiner’s contribution to the development of the periodic table

Chemistry
1 answer:
erastova [34]4 years ago
5 0

John Dobereiner proposed the idea of similarity in the properties of elements which can be placed together.

He proposed the idea of classification so that we can study the properties of a group of elements together

According to him, three elements can be grouped based on their similarities in properties. This group of three elements was termed as "Triads"

For example :

Li, Na, K

Now the significance of the triad was that the atomic weight of middle element is average of atomic weights of the side atoms

So atomic weight of Na = 23 is average of atomic weights of Lithium and Potassium

7 + 39/2 = 46/2= 23

The other triads were

Ca Sr Ba

Cl Br I

S Se Te


You might be interested in
How many moles of propane
cupoosta [38]
Starting mass: 294
Mass ratio: 3/5
6 0
2 years ago
Write the molecular formula for a compound with the possible elements c, h, n and o that exhibits a molecular ion at m+ = 91.043
timama [110]
We are given the mass spectrum data for this compound which has a molecular ion peak of m+ = 91.043 m/z. When we have an m+ peak that is an odd number, that suggests that there are an odd number of nitrogens, in this case we'll assume 1 nitrogen atom to start. Nitrogen has a mass of 14 so we will substract that from our initial value.

91- 14 (1N) = 77 m/z

We are also told that there are carbon, hydrogens and oxygens present, so we will assume there is at least one oxygen which has a mass of 16 and subtract that value.

77 - 16 (1 O) = 61 m/z

Now we will try to get as close as possible to the remaining mass with carbons that has a mass of 12, and fill the remaining mass with hydrogens that have a mass of 1.

61 / 12 = 5
5 x 12 = 60

61 - 60 (5 C) = 1 m/z and this leaves us with 1 H.

The current formula would be C₅HON, but this structure is impossible since we do not have enough hydrogens to satisfy the carbons. So we can try to use 4 carbons instead and fill the rest with hydrogens.

4 x 12 = 48
61 - 48 (4 C) = 13 m/z and this leaves us with 13 H.

The current formula would be C₄H₁₃ON. The most hydrogens we can have in a compound is 2n+2 where n is the number of carbons. So with 4 carbons the most hydrogens we could have is 10. Therefore, our formula has too many hydrogens and also cannot work. So we cannot make up the remaining mass with carbons and hydrogens, therefore, we should add another oxygen before working with carbons and hydrogens.

61 - 16 (1 O) = 45 m/z
45/ 12 = 3.75
3 x 12 = 36

45 - 36 (3 C) = 9 m/z which gives us 9 hydrogens left.

The current formula is now C₃H₉O₂N. To test if this formula works we can calculate the double bond equivalents (DBE), also known as degrees of unsaturation.
DBE = C - H/2 + N/2 + 1 = 3 - (9/2) + (1/2) + 1 = 0

A value of 0 DBE tells us that there are no double bonds in this molecule but that the formula is a possibility so:

C₃H₉O₂N = 91 m/z
8 0
3 years ago
At room temperature, what is the only metal that is in liquid form?
Olenka [21]

Hello!

Mercury is the only metal that takes liquid form at room temperature.

The metal is also very toxic to humans, so "playing with it" is a bad idea

this metal used to be used in thermometers, but most of them today don't use mercury anymore

I hope this helps, and have a nice day!

3 0
3 years ago
Why does a perfume bottle burst when placed inside the flame​
madreJ [45]

Answer:

It's because the perfume bottle contains ethyl alcohol.

6 0
3 years ago
Read 2 more answers
The liquid state of matter can be described as
wariber [46]
Having a definite volume but not a definite shape.
3 0
3 years ago
Read 2 more answers
Other questions:
  • Photosynthesis produces
    9·1 answer
  • Classify each of the following properties by writing physical or chemical matter
    12·1 answer
  • Paige heated 3.00 g mercury (II) oxide (HgO, 216.59 g/mol) to form mercury (Hg, 200.59 g/mol) and oxygen (O2, 32.00 g/mol). She
    13·2 answers
  • The periodic table is divided into different blocks. Elements that have complete valence electron shells are mostly found in the
    7·2 answers
  • 1. Based on this graph, how does metal A differ from metal B?
    10·1 answer
  • Consider the following precipitation reaction (balanced). precipitation reaction: 2NH4Br(aq)+Pb(C2H3O2)2(aq)⟶2NH4C2H3O2(aq)+PbBr
    7·1 answer
  • A concrete barrier in a parking lot a structure of mass, frame, or shell? Which one would it be?
    14·1 answer
  • Layer B in the diagram is located between the crust and core in terms of location, temperature, and pressure. What part of the e
    13·2 answers
  • CO2, NaCI, and HCI may all be classified as...
    10·2 answers
  • The diagram shows the breathing system in a human. What does label 1 show?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!