what was johann dobereiner contribution to the periodic table

Answers

Answer 1

Answer:

he introduced triads of similar chemical properties in periodic table.

Explanation:


Related Questions

for the reaction, Pb(no3)2 + 2kI yields pbi 2 + 2 kno3, how many moles of lead iodine are produced from 300 g of potassium iodine

Answers

Good its true no problem plus 222-333

explain why almunium is often used for long distance over head electric cables (high voltage)​

Answers

Answer:

because it does not cost much and can be found easily.  due to their low resistance and excellent conductivity.

Explanation:

Which model of the atom is thought to be true?

A. Protons, electrons, and neutrons are evenly distributed throughout the volume of the atom.
B. The nucleus is made of protons, electrons, and neutrons.
C. Electrons are distributed around the nucleus and occupy almost all the volume of the atom.
D. The nucleus is made of electrons and protons.

Answers

Its A. Explanation:I just know

noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?

Answers

Answer:

Noble gases have a complete valence electron shell making them stable and nonreactive.

Explanation:

Alkaline batteries adopted their name from the _____ that is present in the reactions at both the zinc anode and the MnO2 cathode.

Answers

Answer:

hydroxide ion

Explanation:

The alkaline battery got this name because it has an alkaline electrolyte of potassium hydroxide.

9
Ammonia is manufactured from nitrogen and hydrogen by the Haber process.
N2(g) + 3H2(g)2NH3(g)
What is the percentage yield when 60 kg of ammonia is produced from 60 kg of hydrogen?
A
5.9%
B
17.6%
с
35.3%
D
50.0%

Answers

Answer:

B

17.6%

Explanation:

1. Percentage yield = (Actual yield/theoretical yield) x 100

2. You know actual yield of ammonia (60kg) so you need to work out theoretical yield.

3. mols of hydrogen = m/mr = 60,000/2 = 30,000 mols.

4. 3:2 ratio so (30,000/3) x 2 = 20,000 mols of Ammonia.

5. Therefore mass of ammonia = mr x mols = 20,000 x 17 = 340,000 grams

6. So percentage yield is (60,000/340,000) x 100 = 17.6

Different isotopes of an element have different numbers of:

Answers

Explanation:

Different isotopes of an element have different numbers of mass number

20 points be right this is my final!!!

Answers

I think it’s c hope it helps.

Multiply or divide to find the equivalent fraction.

51/120=□/360

Answers

Answer

153

Explanation:

51/120 = x/360

51(360) = 120x

18360 = 120x

18360/120x = 120x/120x

153 = x

Answer:

153

Explanation:

Write a balanced equation and name the products of the reaction CaCl2+Na3(PO4)

Answers

Answer:

3CaCl2 + 2Na3(PO4) → Ca3(PO4)2 + 6NaCl

Explanation:

DOUBLE REPLACEMENT REACTION

CaCl2 + Na3(PO4) → Ca3(PO4)2 + NaCl

3CaCl2 + 2Na3(PO4) → Ca3(PO4)2 + 6NaCl

calcium chloride + sodium phosphate → calcium phosphate + sodium chloride

Hope that helps

Match each type of reaction to its amount of potential energy. (PLEASE HELP )

Answers

Endo is more in reactants and exo is more in products because in exothermic reactions heat is released

Read this sentence from Chapter One of Jack London’s The Call of the Wild.

Buck rushed at the splintering wood, sinking his teeth into it, surging and wrestling with it. Wherever the hatchet fell on the outside, he was there on the inside, snarling and growling, as furiously anxious to get out as the man in the red sweater was calmly intent on getting him out.

What is a good prediction question to ask after reading this excerpt?

Answers

Answer:

b)

Explanation:

It shows the natrual proggresion of a story and helps blend the narrtive together.

Answer:B

Explanation: i took the quiz on edge

what is the speed of a skater who travels a distance of 210 m in a time of 10 seconds

Answers

Answer:

Speed =d/t. 200÷10=21÷1000=0.021 km/h

Explanation:

S=D/T

Which of the following compounds will have the highest boiling point?


MgCl2



CO2


C12H22O12

,

H2O

Answers

MgC12 has the highest boiling point

How does thermal energy flow?

Answers

Answer:

Thermal energy typically flows from a warmer material to a cooler material.

Explanation:

people tint their car windows to stop what

Answers

Answer:

Reflection

Explanation:

Answer:

b

Explanation:

how to tell if something is a strong or weak acid or base

Answers

Answer:

It basically depends upon the pH value of that acid or Base. That's how you can determine whether the substance is a strong or weak acid/base. We have a pH scale ranging from 1 to 14, where 7 is the neutral point. Any substance having a pH of 7 means it is neither an acid nor a Base, but neutral in nature, such as water([tex]H_{2}O[/tex]). Now, if the pH is less than 7, the substance is an acid, similarly if the pH is more than 7, it is a base. As the pH DECREASES, the substance becomes more acidic, on the other hand as the pH INCREASES, the substance becomes more basic. This way you can compare between pH values of two substances and tell which one is stronger or weaker.

For Acids:

If a substance's pH is between 1 and 7 it is an acid. If it is more towards 1, it's a strong acid and if it's more towards 7 it is a weak acid.

For Bases:

If a substance's pH is between 7 and 14 it is a base. If it is more towards 14, it's a strong base and if it's more towards 7 it is a weak base.

Hope that helps...

A molecular compound is found to consist of30.4% nitrogen and 69.6% oxygen. Ifthe molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule

Answers

Answer:

92.01 g/mol

Explanation:

So first you need to find the empirical formula by the percents. That would be, assuming that you have 100 grams of the the sample, divide each quantity of each element found by its respective molar mass.

30.4 g of N ÷ 14 g/mol N= 2.17 mol of N

69.6 g of O ÷ 16g/mol= 4.35 mol of O

You can establish now the empirical formula.

N2.17O4.35,

but since you can't have a decimal subscript, you divide each subscript by the minimum subscript

NO2

So then you're said that the molecular formula derived from that empirical formula has 2 nitrogen, so you multiply all the subscripts, by 2:

N2O4

-Dinitrogen Tetraoxide

-Nitrogen oxide (IV)

Then all you have to do is find the molecular mass of the compound using the periodic table and what you obtain is the molar mass.

remember: molecular mass is correspondent to molar mass.

Elements that become cations during bonding become smaller as a result.
A.
True

B.
False

Answers

It’s False sorry if it’s wrong but I hope it help

What is the mass number (A) of an atom that has an atomic number (Z=26) with 29 neutrons and 26 electrons?​

Answers

Answer:

A = 55

Explanation:

The atomic number is the number of protons also = the number of electrons, so basically we have 29 neutrons, 26 electrons and 26 protons. Anyway, it's asking the mass number which is the neutrons + the protons, so you just take 29+26 = 55

Atomic number=26

Neutrons=29

Electrons=26

Mass number=Proton+neutron

Protons=26

Mass number=26+29

=55

This is my class group-work with my friends but we are stuck on this question.

Answers

Explanation:

It has to be C, because Carbon can bond with four other atoms and is like a four-hole wheel.

(Sorry if my elplanation was kinds choppy Oof, helpfully it makes sense?)

What happens when a solid is exposed to sub-zero temperatures?

Answers

Answer:

A substance may undergo phase change from a solid to a gas or from a gas to a solid if the temperature it is exposed to is changed very quickly. If the temperature around a solid is raised very quickly, it can sublimate, or phase change from a solid to a gas without existing as a liquid.

Explanation:

how many atoms of mercury are in 50.15 g of mercury?

Answers

Answer:

please mark brainliest

Explanation:

The correct answer to this question is 0.2500 mol

Formula to calculate moles:

Moles = mass ÷ molar mass (n=m/M)

Mass = 50.15g

Atomic mass: 200.59 amu

Moles = 50.15g/200.59

= 0.2500 mol.

which particle diagram shown above best represents the strongest intermolecular force between two ethanol, c2h6o, molecules?

Answers

The strongest intermolecular bonding in ethanol is hydrogen bonding.

Intermolecular forces are the forces that hold two molecules of a substance together in a given state of matter. For ethanol, the strongest intermolecular force is hydrogen bonding.

Hydrogen bonding occurs when hydrogen is directly linked to a highly electronegative element such as oxygen, nitrogen, fluorine or sulfur. The existence of intermolecular hydrogen bonds accounts for unusual properties such as abnormally high melting and boiling points.

Learn more about intermolecular forces: https://brainly.com/question/17111432

how many grams are in 4.07x10^15 molecules of calcium hydroxide

Answers

There are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.

HOW TO CALCULATE MASS:

The mass of a substance can be calculated by multiplying the number of moles in the substance by its molecular mass.

However, given that the number of molecules in calcium hydroxide is 4.07 x 10¹⁵molecules, we need to calculate the number of moles in Ca(OH)2 as follows:

no. of moles of Ca(OH)2 = 4.07 x 10¹⁵ ÷ 6.02 × 10²³

no. of moles = 0.676 × 10-⁸

no. of moles = 6.76 × 10-⁹ moles.

Molar mass of Ca(OH)2 = 74.093 g/mol

Mass of Ca(OH)2 = 74.093 × 6.76 × 10-⁹ moles

Mass = 5.01 × 10-⁷grams.

Therefore, there are 5.01 × 10-⁷grams in 4.07 x 10¹⁵molecules of calcium hydroxide.

Learn more about how to calculate mass at: https://brainly.com/question/8101390?referrer=searchResults

If a sample of gas at constant temperature has its pressure doubled, what will happen to its volume?

Answers

Answer:

it'll halve

Explanation:

the gas is compressed with twice the pressure. The volume will be halved.

im certain

How many moles is 2.50 grams of oxygen?

Answers

Answer:

Mole is a number that connects mass of a substance with its number of particles. 2500 g of O2 = 1/32 x 2500 = 78.125 moles

Explanation:

have a great day

Look at the graph. Which part of the line shows a time
when the object was not moving?

Answers

B.

For the period of B, the line didn’t go up or down, it stayed still.
this shows that time was still passing but the car didn’t move.

Which of the following statements is true about atomic spectra? I. The line spectra of elements are evidence that electron energies are quantized II. Energy is emitted from atoms as they move from lower energy levels to higher energy levels III. Energy is emitted from atoms as they move from higher energy levels to lower energy levels IV. Neutral atoms in the ground state emit light spontaneously

Answers

The line spectra of an atom offers conclusive evidence that electron energies are quantized.

Neils Bohr showed that electrons in an atom can absorb or emit energy when they move from one energy level to another. This principle is the basis upon which the spectra of atoms is built.

The true statements about the atomic spectra is;

The line spectra of elements are evidence that electron energies are quantized Energy is emitted from atoms as they move from higher energy levels to lower energy levels

Learn more about atomic spectrum: https://brainly.com/question/2049494

PLEASE DON'T PUT ANSWER AGAINST GUIDELINES!!!

Answers

Answer:

160.3 g S

Explanation: there you go

Other Questions
1. A roller coaster with a mass of 800 kg sits stationary at the top of a section of track, 75 m abovethe ground as shown. When the brake is released, it starts to roll down the track2. For each height represented in the diagram, calculate the gravitational potential energy usingEp = mgh. Show ONE SAMPLE calculation in the calculations section below and fill in Table 1 foreach of the heights of the roller coaster. (6 marks)3. Assuming there is no friction, determine the mechanical kinetic energy using Ek = Etotal - Ep.Show ONE SAMPLE calculation in the calculations section below and fill in Table 1 for each ofthe heights of the roller coaster. (6 marks)4. For each height represented in the diagram, calculate the velocity using = 2 . Show ONESAMPLE calculation in the calculations section below and fill in Table 1 for each of the heights ofthe roller coaster. (6 marks)5. Use your answers to graph how gravitational potential energy, mechanical kinetic energy, andvelocity change as the roller coaster changes height. Use different colours for the three lines onthe graph. Graph paper is provided below. (3 marks)6. Repeat steps 1 5 above for a roller coaster cart that has a mass of 300 kg and enter yourresults in Table 2.Calculations:800 kg roller coaster cart:Sample calculation for gravitational potential energy:Sample calculation for Mechanical kinetic energy:Sample calculation for velocity:300 kg roller coaster cart:Sample calculation for gravitational potential energy:Sample calculation for mechanical kinetic energy:Sample calculation for velocity:Results:Table 1: Potential energy, kinetic energy, total energy, and velocity of the 800 kg roller coaster cartTable 2: Potential energy, kinetic energy, total energy, velocity of the 300 kg roller coaster cart.Graphs:Its graphing time. These graphs are a bit different than the ones you did in thedata analysis assignment at the beginning of the course. In this case you havethree things to graph on each graph. (One graph for the 800 kg roller coaster cartand one graph for the 300 kg roller coaster cart.) You need to graph thegravitational potential energy with respect to height, the mechanical kineticenergy vs height, and the velocity vs height.Lets look at the energy graphs first. In this case both kinetic energy andmechanical energy cover the same range of values. This means they can use thesame scale on the y-axis. So, you will use the left y-axis and the x-axis to graphthe kinetic energy vs height and the potential energy vs height. You will need alegend to explain which line is which. Colour coding is a nice way to highlight this.The velocity values are much different than the energy values. This means youneed a totally different scale. So, your left y-axis wont work. You need to make asecond scale on the right y-axis for your velocity values. You will plot the pointsthe same way as normal, but you will use the numbers on the right-hand scaleinstead. Again, be sure to add your velocity line to the legend with a separatecolour code.Discussion Questions:1. Describe the relationship between the gravitational potential energy and the mechanical kineticenergy of the roller coaster on your graph. (2 marks)2. Describe the shapes of each of the three lines in the graph. Explain why the velocity is different.(4 marks)3. Describe how mass affects the speed at the bottom of the roller coaster. (2 marks)4. Describe how mass affects the gravitational potential energy and the mechanical kinetic energyof the roller coaster. (2 marks)5. At what point does the roller coaster have a maximum value for the following? Justify youranswer by explaining why. (2 marks each)a. Gravitational potential energyb. Mechanical energyc. Velocity6. In your calculations, you assumed that the roller coaster was frictionless. All real roller coastersencounter friction. Describe how the actual values of the variables would differ, or not differ,from your calculated values for a real roller coaster. (Hint: what form of energy would some ofthe total energy be converted to if there was friction in the system?) (4 marks)How you will be graded:Grades will be based on answering questions to demonstrate an understanding of the material coveredin this unit. Point form answers are okay if ideas are complete and use vocabulary (Word Bank)provided. For questions out of 4 marks, there are 4 responses expected. write any 4 causes of rareness of bengar tiger? Please help Ill mark brainliest!!! The Circumference of Taylors bike tire is 72 inches what is the diameter of the tire used 3.14 for and round to the nearest whole number What is the simplified form of ? 5000 5000 100 100. Find the factors of f(x) given that x = 3 is a zero.f(x) = x^3 + 12x^2 + 47x + 60 (x + 3)(x + 4)(x 5) (x + 3)(x + 4)(x + 5) (x 3)(x + 5)(x + 6) (x + 3)(x + 3)(x 3) Estimate 4 1/3 x 2 3/4 What is the correct answer for this? 3. A(n)______ is someone who travels to new places or does new things. A. explorer B. thrill C. expedition D. research If the price of a good doubles and quantity supplied triples, then Which of the following is NOT aresponse that the body would haveto a stimuli?A. physical responseB. chemical responseC. creating a feelingD. evolving the body I need help with this Put the following equation of a line into slope-intercept form, simplifying all fractions.9x3y=9x3y=12 This program is an example of:def factorial(x): if x == 1: return x else: return x * factorial(x-1)Group of answer choicesa do while loop.recursion.a for loop.a while loop. Group which shows similar traits that is different from the other descendants of a common ancestor. Look at the examples in highlighted text in the passage. Which one supports the theme Of knightly virtue? Choose the option that best combines these sentences into a logical compound sentence.Stina is extraordinarily good at playing billiards. I've never dared to play with her.Choose 1 answer.: Stina is extraordinarily good at playing billiards, so I've never dared to play with her.B: Stina is extraordinarily good at playing billiards, I've never dared to play with her.C: I've never dared to play with Stina; really, extraordinarily good at playing billiards. Chromosomes on a karyotype are arranged from largest to smallest. True False Determine the amplitudeor period as requested.Period of y = 4sin 1/3xa. 4 b. Pi/4c. 4pi/3d. 6pi Answer this for me please!! This is for the ones who knows and speak Spanish