Johann Döbereiner identified triads of chemically related elements in 1829 and demonstrated how the properties of the middle element could be anticipated from the properties of the other two. Examples of such triads are lithium, sodium, and potassium.
How did the idea of triads influence the development of the periodic table?
Johann Dobereiner (1780–1849), a German scientist, organized diverse trios of three elements into triads in 1829.Lithium, sodium, and potassium made up one such trio.Triads were based on both chemical and physical characteristics. All known elements could fit on Mendeleev's periodic table, and it also made precise predictions about the presence and characteristics of yet-to-be-discovered elements. Mendeleev organized the elements in his first periodic table according to their masses and other chemical characteristics.Atoms' fundamental chemical structure was unknown at the time.Mendeleev increased the size of his periodic table to include every element at the time. The law of triads was discovered by German scientist Johann Döbereiner, who wrote: "If the elements with similar chemical properties are grouped in the groups of three, the atomic weight of the middle element will be deemed almost equivalent to the arithmetic mean of the two-terminal element's total." The arithmetic mean of the atomic masses of the first and third elements must be about equal to the atomic mass of the second element in order to form a Dobereiner trio.The atomic mass of nitrogen is equal to the arithmetic mean of the atomic masses of carbon and oxygen in this situation, which is 14.They so make up Dobereiner's trio.To learn more about periodic table refer
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The first organisms to arrive in an ecosystem?
need these 2 answered asap pls
Answer:
im not a brain wiz but i think 20
Explanation:
what is bank?Effect of drug abuse.
- Long term effects
Chronic drug use can alter a person’s brain structure and function, resulting in long-term psychological effects, such as: depression, anxiety, panic disorders, increased aggression, paranoia, hallucinations.
- Cardiovascular disease
Stimulants, such as cocaine and methamphetamines, can damage the heart and blood vessels. The long-term use of these drugs can lead to coronary artery disease, arrhythmia, and heart attack.
- Respiratory problems
Drugs that people smoke or inhale can damage the respiratory system and lead to chronic respiratory infections and diseases. Opioids slow a person’s breathing by binding to specific receptors in the central nervous system that regulate respiration. By depressing a person’s respiration, these drugs can lead to slow breathing or heavy snoring.
- Kidney damage
The kidneys filter excess minerals and waste products from the blood. Heroin, ketamine, and synthetic cannabinoids can cause kidney damage or kidney failure.
- Liver disease
Chronic drug and alcohol use can damage the liver cells, leading to inflammation, scarring, and even liver failure.
- Overdose
Taking too much of a drug or taking multiple drugs together can result in an overdose. According to the Centers for Disease Control and Prevention (CDC), drug overdose caused 67,367 deathsTrusted Source in the United States in 2018. Opioids contributed to nearly 70% of these deaths.
How to get help:
Finding the right treatment program can be a daunting task. Here are a few things to think about when seeking treatment for drug abuse, misuse, or addiction:
consider whether inpatient or outpatient services would be the best fit
find local treatment centers using this resource from the Substance Abuse and Mental Health Services Administration
note that state-run treatment centers and programs can be free of charge
look for programs that use evidence-based treatment strategies
As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution?
A) Decreases
B) Increases
C) Remains the same
B) increasesAnswer:
Explanation:
As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution increases. Therefore, the correct option is option B.
What is mole?The World System representing Units (SI) uses a mole (symbol mol) as the unit of material amount. How many fundamental entities of a particular substance are present in an object and sample is determined by the quantity of that material. An elementary entity can be a single atom, a molecule, a pair of ions, an ion pair, even a subatomic particle like a proton depending on the makeup of the substance.
For instance, although having differing volumes and masses, ten molecules of liquid (a chemical compound) because 10 moles of mercurial (a chemical element) both have the same quantity of substance, because the mercury has exactly one atom every every molecular structure of the water. As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution.
Therefore, the correct option is option B.
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Beryllium hydrogen carbonate is more than 3% hydrogen by mass.
True
False
6. Calculate the new pressure in atm if 2.45 L of a gas at a pressure of 1.20 atm is contracted to a new
volume of 2.20 L
Answer:
[tex]\boxed {\boxed {\sf x \approx 1.34 \ atm}}[/tex]
Explanation:
Since we are dealing with temperature and pressure, we must use Boyle's Law. This states that the pressure is inversely proportional to the volume. The formula is:
[tex]P_1V_1=P_2V_2[/tex]
Where P is the pressure and V is the volume.
We know the original pressure (P₁) of the gas is 1.20 atmospheres and the volume (V₁) is 2.45 liters.
[tex]1.20 \ atm * 2.45 \ L = P_2V_2[/tex]
We also know the gas is contracted to a new volume of 2.20 liters (V₂) , but we do not know the pressure (P₂). We can use x.
[tex]1.20 \ atm *2.45 \ L = x * 2.20 \ L[/tex]
We can solve the left side of the equation and multiply.
[tex]2.94 \ atm *L= x*2.20 \ L[/tex]
We are trying to find the new pressure (x), so we must isolate the variable. It is being multiplied by 2.20 liters. The inverse of multiplication is division, so we divide both sides by 2.20 L.
[tex]\frac {2.94 \ atm *L}{2.20 \ L}=\frac{x*2.20 \ L}{2.20 \ L}[/tex]
[tex]\frac {2.94 \ atm *L}{2.20 \ L}=x[/tex]
The units of liters cancel.
[tex]\frac {2.94 \ atm}{2.20 \ }=x[/tex]
[tex]1.33636363636 \ atm =x[/tex]
The original measurements have 3 significant figures, so our answer should have the same. For the number we found, that is the hundredth place.
The 6 in the thousandth place tells us to leave the 3 in the hundredth place.
[tex]1.34 \ atm \approx x[/tex]
The new pressure is approximately 1.34 atmospheres.
If you stay at 90 degrees Celsius and a gas in a liquid solution has a pressure of 2 atm, what solubility should it have if it has a solubility of 64 g/L at a pressure of 8 atm?
Answer:
im not sure
Explanation:
What volume of hydrogen sulfide gas will be collected if
39.0 grams of sodium sulfide are reacted?
Answer:
yes
Explanation:
Answer:
578.....882...767..86
How many moles of Co are needed to produce nine moles of CO2
Answer:
guizzes
Explanation:
guizlet
Answer:
2. 8 moles of carbon dioxide can be produced from 12.5 moles of oxygen. 1 mole of octane can be produced from 8 moles of carbon dioxide gas.
Explanation:
hope this helps :)
Select the correct answer.
A circuit is used in which process?
OA. electricity
OB. magnetism
OC. velocity
OD. gravity
Answer:
electricity
Explanation:
A circuit is used in every electrical and electronics operation.
What is the enthalpy of reaction for the decomposition of calcium carbonate?
CaCO3(s) Right arrow. CaO(s) + CO2(g)
A 2-column table with 6 rows. Column 1 is labeled Compound with entries upper C a upper O solid, Upper C a upper C upper O subscript 3 solid, Upper C subscript 6 upper H subscript 6 gas, Upper C upper O subscript 2 gas, Upper H subscript 2 upper O gas, Upper N upper O subscript 2 gas. Column 2 is labeled Delta H subscript f in kilojoules per molecule with entries negative 157.3, negative 1,207.1, 82.90, negative 393.5, negative 241.82, 33.84.
Answer:
First Blank: 656.3 kJ
Second Blank: Endothermic
Explanation:
Edge 21'
Answer:
1. 656.3
2. endothermic
Explanation:
cells, Cell Division)
1. Which of the following statements is NOT part of the cell theory?
a. Cells are the basic unit of structure and function in living things
b. All cells are produced from other cells.
C. Only animals are composed of cells.
d. All living things are composed of cells.
Answer:
c is wrong
Explanation:
If 500 mL expandable cylinder with a pressure of 500
mmHg was filled until the volume was 1.2 atm. What is the
new volume?
Answer:
0.274 L
Explanation:
Applying Boyle's law,
PV = P'V'................. Equation 1
Where P = Initial pressure, V = Initial volume, P' = Final pressure, V' = Final volume.
make V' the subject of the equation,
V' = PV/P'............. Equation 2
From the question,
Given: P = 500 mm Hg, V = 500 mL = 0.5 L, P' = 1.2 atm = 912 mm Hg
Substitute these values into equation 2
V' = (0.5×500)/912
V' = 0.274 L
Hence the new volume is 0.274 L
A student was in the lab testing the conductivity of different solutions. Three of the solutions were NaNO3, Ca(NO3)2, and Al(NO3)3. Which of the solutions should be the best conductor of electricity?
Answer:
Aluminium nitrate
Explanation:
[tex]Al(NO _{3}) _{3}[/tex]
This is because there are many conducting nitrate ions compared to the other electrolytes
6)
Which formula can represent
an
alkyne?
A)
C₃H6
B)
C₂H4
C)
C3H4
D)
C₂H6
Answer:
c)C3H4
Explanation:
Answer: C. C3H4
Explanation:
I got it wrong and castle learning showed me the answer
what will litmus paper turn when it reacts with sodium nitrate?
The solid dissolves quickly is a chemical or physical reaction
Answer:
i think it is chemical wait no physical
Explanation:
Two glass rods are rubbed together. One of the glass rods are brought near (but
does not touch) an uncharged pith ball. Would you expect the pith ball to attract,
repel, or do nothing? Explain why.
Answer:
Do Nothing
Explanation:
Charges are transferred by friction when two different types of bodies are rubbed together. This is known as charging by friction.
However, when two materials of the same type are rubbed together, no charge is transferred from one object to the other hence there is no transfer of charges by friction and none of the two glass rods are charged.
Therefore, when one of the glass rods is brought close but does not touch the pith ball, nothing happens.
Calculate the pOH for a solution with a pH of 12.34. Is the Solution acidic or basic?
Answer:
1.66 basic
Explanation:
6) What is the picture below an example of?
Answer:
The picture below is an example of a food chain.
Explanation:
The bug (can't tell which one by the picture) eats the grass, the frog eats the bug, the snake eats the frog, and the eagle eats the snake.
PLZ HELP!!!!!! IN YOUR OWN WORDS PLZ! :D
Imagine your cell phone rings. Describe how the sound gets transmitted from your phone to your ear, and then, from your ear to your brain. In your response, be sure to mention the type of wave that a sound wave is, the medium the sound is transmitted through before it gets to your ear, and what happens in your ear once the sound reaches it.
Answer:
SOUND WAVE (carried by thin metal inside the phone) ⇒ELECTRICAL ENERGY (over the wire) ⇒SOUND WAVE (that is heard by someone on the side of the phone)
Explanation:
What is a sound wave?A wave that is comprised of compression and refraction, by which sound is propagated in an elastic medium such as air.
How does sound get transmitted from phone to ear?
The sound waves are carried to a thin metal disk inside the phone, known as the diaphragm, and are converted into electrical energy. The electrical energy travels over wires to another phone and is converted from electrical energy to sound waves again which can be heard by the one on the other end of the phone.
How does sound get transmitted from ear to brain and what happens when sound reaches the ear?Sound waves enter the outer ear and travel through a small passageway (ear canal), which leads to the eardrum.The eardrum vibrates from the coming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are known as the malleus, incus, and stapes.The bones present in the middle ear amplify the sound vibrations and send these vibrations to the cochlea (the snail-shaped structure that is filled with fluid present in the inner ear). An elastic separation runs from the beginning to the edge of the cochlea, splitting it into upper and lower parts. This separation is called the basilar membrane as it serves as the base on which key hearing structures sit.Once the vibrations result in the fluid inside the cochlea rippling, a traveling wave appears along the basilar membrane. Hair cells (sensory cells) sitting on top of the basilar membrane ride the wave. Hair cells near the broad end of the cochlea detect higher-pitched sounds. Those closer to the center detect lower-pitched sounds, such as a large dog barking.As the hair cells move up and down, microscopic hair-like projections (known as stereocilia) that perch on the peak of the hair cells crash against an overlying structure and bend down. Bending results in pore-like channels, which are at the tips of the stereocilia, opening up. Then chemicals rush into the cells, producing an electrical signal.The auditory nerve carries this electrical signal to the brain, which in return it into a sound that we recognize and understand.In this way, sound reaches our ears.
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calculate the mass in 0.0040 moles of potassium permanganate
Where on the periodic table are you most likely to find elements that do not react with other elements A) group 1 B) group 2 C) group 17 D) group 18
Answer:
d) group 18
Explanation:
Group 18 on the periodic table consists of noble gasses, which do not chemically interact with other elements.
En una muestra de jugo de limón la concentración de H1 es de 3.8x10 a la 4 potencia ¿ cual es su PH considerando que 378= 0.58
Answer:
pH = 3.42
Explanation:
Para calcular el pH necesitamos usar la siguiente expresión:
pH = -log[H⁺]
Por tanto, solo necesitamos reemplazar el valor dado de [H⁺] en la expresión anterior y se determina su pH:
pH = -log(3.8x10⁻⁴)
pH = 3.42Por tanto el pH de la muestra de jugo de limón es 3.42
How many moles of NaOH
would you have in a
sample that weighed 10g?
Answer: There are 0.25 moles of NaOH in a sample that weighed 10g.
Explanation:
Given: Mass of NaOH = 10 g
Molar mass of NaOH is 40 g/mol.
Number of moles is the mass of substance divided by its molar mass.
Therefore, moles of NaOH are calculated as follows.
[tex]No. of moles = \frac{mass}{molarmass}\\= \frac{10g}{40 g/mol}\\= 0.25 mol[/tex]
Thus, we can conclude that there are 0.25 moles of NaOH in a sample that weighed 10g.
What is important in order for a radioisotope to provide accurate dating
results?
O A. The half-life should be similar to the age of the object.
B. The radioisotope cannot be part of a decay chain.
O C. The isotope must undergo transmutation.
O D. The item being dated must be very old.
The most important factor to be considered in order for a radioisotope to provide accurate dating simply is:
The half-life should be similar to the age of the object.
The correct answer choice is option a.
Why half-life should be similar to the age of the object in determining accurate dating of a radioisotope.Half-life of radioisotope helps in determining dating accurately simply because it helps to predict the amount of radioactive substance remaining after a given period of time.
In conclusion, it can be perfectly deduced from the explanation given above that the half-life of a radioisotope usually, frequently and most of the time helps to determine the rate at which these substances decay.
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How much energy is required to change 75 grams of copper at 35 degrees Celsius
to liquid copper at 1200 degrees C?
34950 J of energy is required to change 75 grams of copper at 35 degrees Celsius to liquid copper at 1200 degrees Celsius.
What is Specific Heat?The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
It is given by the formula -
Q = mcΔT
where, Q = amount of heat
m = mass
c = specific heat
ΔT = Change in temperature
Given,
Mass of copper = 75g
ΔT = ( 1200 - 35) = 1165⁰C
c = 0.4 J/g ⁰C
Q = mcΔT
= 75 × 0.4 × 1165
= 34950 J
Therefore, 34950 J of energy is required to change 75 grams of copper at 35 degrees Celsius to liquid copper at 1200 degrees Celsius.
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Which of these has a bond that takes the most energy to break?
a) Brz
b) N,
c) 02
d) HCI
Answer:
Hello! Your answer would be, D) HCI
Explanation:
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PLS HELP ASAP NO LINKS
What type of scientist studies matter and its composition?
Biologist
Chemist
Physicist
Engineer
Answer:
.biology and maybe physics
Answer:
Biologist
ExplanationBiologist Unlike the above type of scientist, geoscientists’ work involves exploring the earth and its internal environment. They study the composition, structure, and processes of the earth by being indoors and outdoors. They contribute to the discovery of mines, petroleum deposits, minerals, and other aspects of the earth.
Draw Conclusions does the F2 generation support that lack of wings is a genetic trait? Explain why or why not
Answer:
An F1 offspring could produce four types of gametes, RY, Ry, rY, and ry. The F2 generation supports the independent-assortment model and refutes the linkage model.
Explanation: