Answer: B. Nickel Copper Zinc
Explanation:
Dobereiner's triads was a group of three elements. Dobereiner said that the relative atomic mass of the middle element in each triad was average of the relative atomic masses of the other two elements.
Thus if A, B and C forms Dobereiner's triads, the mass of B is average of mass of A and C.
A. Hydrogen Oxygen Nitrogen:
mass of oxygen = 15.999
mass of oxygen according to Dobereiner = [tex]\frac{1.008+14.007}{2}=7.5075[/tex]
B. Nickel Copper Zinc
mass of copper = 63.5
mass of copper according to Dobereiner = [tex]\frac{58.7+65.38}{2}=62.04[/tex]
C. Aluminum Gallium Indium
mass of gallium = 69.72
mass of gallium according to Dobereiner = [tex]\frac{26.98+114.82}{2}=84.39[/tex]
D. Neptunium Plutonium Americium
mass of Plutonium = 244
mass of Plutonium according to Dobereiner = [tex]\frac{243+237.04}{2}=240.02[/tex]
which rock is the result of changes on the Earth's surface?
igneous rock
sedimentary rock
metamorphic rock
Answer:
metamorphic
Explanation:
when one rock changes another rock the rock that got changed is now metamorphic
The picture provided shows the arrangement of electrons in atomic shells around the nucleus of four different elements.
Which statement is true about these elements?
A) All elements belong to the same period.
B) All elements belong to the same group.
C) Elements 1 and 4 belong to the same group.
D) Elements 2 and 3 belong to the same period.
Both element 1 and element 4 have one electron in their valence shell Therefore, they belong to the same group. Therefore, option (C) is correct.
Why do elements of the same group have similar chemical behavior?The chemical behavior of elements will depend on the number of electrons in their outermost shell. Elements that are placed in the same group have the same number of valence electrons. Therefore, elements present in the same group of the modern periodic table have similar chemical properties.
The elements with a similar outer shell electronic configuration in their atoms are organized in the same group of the modern periodic table. These valence electrons of an element are responsible their chemical properties and reactivities of the elements.
Elements 1 and 4 have one electron in their valence shell so they belong to the same group while elements 2 and 4 have two electrons in their valence shell that also belong to the same group.
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can someone please help me solve this? i dont understand this problem :(
Answer:
–4020 KJ
Explanation:
The following data were obtained from the question:
H₂(g) + F₂(g) —> 2HF(g) ΔH = –536 KJ
Next, we shall determine the mass of H₂ that reacted from the balanced equation to produce –536 KJ of heat energy. This can be obtained as follow:
Molar mass of H₂ = 2 × 1 = 2 g/mol
Mass of H₂ from the balanced equation = 1 × 2 = 2 g.
Summary:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Finally, we shall determine the heat change produced by the reaction of 15 g of H₂. This can be obtained as follow:
From the balanced equation above,
2 g of H₂ reacted to produce –536 KJ of heat energy.
Therefore, 15 g of H₂ will react to produce = (15 × –536)/2 = –4020 KJ of heat energy.
Thus, the heat change for the reaction is –4020 KJ
Synthesis
Decompisition
O Combustion
O Single Displacement
O Double Displacement
Answer:
Synthesis
Explanation:
Nothing else works
If a concentrated solution of acetic acid is 99.5 % HC2 H3 O2 and has a density of 1.05 g/mL, what is the concentration of this acid in moles per litre?
Answer:
[CH₃COOH] = 17.4 M
Explanation:
Acetic acid → CH₃COOH
Molar mass → 60 g/mol
99.5% is percent by mass concentration. It means that 99.5 grams of solute are contained in 100g of solution.
Density → 1.05 g/mL. This data is always referred to solution, not solute!.
We determine solution's volume:
1.05 g/mL = 100 g / V → V = 100 g /1.05 g/mL → 95.2 mL
Now we know, that 99.5 g of acetic acid are contained in 95.2 mL
Let's convert to mmoles → 99.5 g / 60 g/mol = 1.66 moles
We convert solution's volume to L → 95.2 mL . 1L / 1000 mL = 0.0952 L
M (mol/L) = 1.66 mol / 0.0952 L = 17.4 M
how deficiency and excess of chromium
Answer:
The chromium found in foods will not hurt you. But taking excessive chromium supplements can lead to stomach problems and low blood sugar (hypoglycemia). Too much chromium from supplements can also damage the liver, kidneys, and nerves, and it may cause irregular heart rhythm.
How is gamma radiation produced?
Answer:
They are produced by the hottest and most energetic objects in the universe, such as neutron stars and pulsars, supernova explosions, and regions around black holes. On Earth, gamma waves are generated by nuclear explosions, lightning, and the less dramatic activity of radioactive decay.
name a lustrous non- metal ?
Answer:
it is iodine it seems very right
Describe the subatomic particles found in an atom, and
describe each one. Also, describe how they relate to each
other.
pls helpp <3
PWEaseee help mweee ill mark brainliest I just need the answer pls and thank you amazing people
Which of these metals is the least reactive?
in
caldum
sodium
potassium
Answer:
Calcium
Explanation:
It is because sodium and potassium are highly reactive metal i.e. Group 1 but calcium is Group 2 element. So, calcium is least reactive.
Which safety procedure could prevent an accident?
using a fire extinguisher
using glass without chips or cracks
smelling a mixture of chemicals
getting a bandage out of the first aid kit when bleeding
Answer:
B
Explanation:
determine the theoretical yield.
aluminum metal reacts with aqueous nickel II sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. in this reaction 108 grams of aluminum were combined with 464 grams of nickel II sulfate to produce 274 grams of aluminum sulfate.
The question is incomplete, the complete question is;
In this stoichiometry problem, determine the percentage yield:
Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.
Answer:
80%
Explanation:
The correct equation for this reaction is;
2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)
We already know that Al is in excess then NiSO4 is the limiting reactant.
Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass
Molar mass of NiSO4 = 155 g/mol
Number of moles = 464g/155g/mol = 2.99 moles
Number of moles of Al2(SO4)3 = mass/molar mass
molar mass = 342 g/mol
So, Number of moles = 274g/342g/mol = 0.8 moles
Given the stoichiometric reaction equation;
3 moles of NiSO4 yields 1 mole of Al2(SO4)3
2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3
percentage yield is given by; actual yield/ theoretical yield * 100/1
actual yield = 0.8 moles of Al2(SO4)3
Theoretical yield = 1 mole of Al2(SO4)3
Hence;
% yield = 0.8/1 * 100 = 80%
What is the definition of hydro energy
Answer:
a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity.
Explanation
which one of the following groups are decomposers a. algae b. protist c. fungi d. green plants e. photosynthetic bacteria?
Answer:
c. fungi
Explanation:
Decomposers are organisms that breaks down dead and decaying matter in nature. They derived their nourishment by breaking down other complex organic matter.
Fungi are a group of organisms that are mainly decomposers.
They recyclers in nature.
Green plants and photosynthetic bacteria are similar in that they obtain nourishment by the use of light to initiate the reaction between carbon dioxide and water.
Many protists are decomposers but not all.
Horsetails are helpful for treating
bee stings.
fevers.
urinary tract infections.
bleeding injuries.
Answer:
urinary tract infections. B
Explanation:
The electron configuration of an element is 1522s22p63523p6451. Why is this a REPRESENTATIVE element?
A)
All orbitals are completely filled.
B)
The outermost electron is a valence electron.
The outermost electron is added to the p-orbital.
D
The highest s-orbital or p-orbital is partially filled.
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Answer:
NaCl (Na is a metal and Cl is a nonmetal) MgO (Mg is a metal and O is a nonmetal) Al2O3, NaF, Na2O
Explanation:
You have to have a metal and a non metal together for it to be ionic
An electrically neutral atom consists of 15 neutrons,13 electrons, and a number of protons.what is its mass number
Answer:
28
Explanation:
The atom is neutral, which means the quantity of electrons and protons square measure an equivalent. thus if there square measure 13 electrons, there square measure 13 protons. and therefore the nucleon number is neutrons and protons. thus 13+15 is 28
What is an example of an initiation phase for an addition
polymerization reaction?
SELECT AN ANSWER
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH3-CH3 ----> H-O-CH2-CH2-O-H
H-O* + CH2=CH * ----> CH3CH2*
H-O* + CH2=CH2 ----> H-O-CH2-CH2*
Answer:
H-O* + CH3-CH3 ----> H-O-CH2-CH2*
H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction. Therefore, the correct option is option A.
What is polymerization reaction?High-molecular-weight compounds known as polymers are created by the aggregation of several smaller molecules known as monomers. Polymers make up the natural and manmade fibres used in clothes as well as the polymers that have revolutionised society.
Two fundamental methods for creating polymers exist: (a) joining small molecules together by an addition reaction, and (b) joining molecules while getting rid of a stable small molecule like water. Condensation processes, which combine addition and elimination reactions, are what this later type of polymerization is known as. H-O* + CH[tex]_3[/tex]-CH[tex]_3[/tex] → H-O-CH[tex]_2[/tex]-CH[tex]_2[/tex]* is an example of an initiation phase for an addition polymerization reaction.
Therefore, the correct option is option A.
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When do you identify your variables?
After the results
After the conclusion
Before the hypothesis
Before the question
Answer:
Before the hypothesis
Explanation:
Explain how the need for energy is the driving force of the oxygen cycle.
Yet again earth science
Answer:
Engery is the driving force of the oxygen cycle is photosynthesis itself, which is responsible for the creation and maintenance of earth's atmosphere.Plants are able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Answer:
Energy is the main force of the oxygen cycle and not to mention also photosynthesis, which is responsible for the creation of the earth's atmosphere. This would also mean that plants are the main focus of the Oxygen cycle and energy is needed to make plants. So without energy, no plants would exist! Not to mention the oxygen cycle wouldn't work without energy. Plants are also able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates and oxygen.
Hope this helps! :)
Explanation:
1 Aluminum reacts with oxygen to produce aluminum oxide, what is the chemical equation?
Answer: Aluminum reacts with oxygen to produce aluminum oxide as follows: 4Al + 3O2 → 2Al2O3 a.
Explanation: I really really hope that was helpful.
What is a photon???????????
A photon is a fundamental particle of light that carries energy and behaves both as a particle and a wave.
It carries electromagnetic waves like visible light, radio waves, X-rays, and gamma rays. Photons have energy, momentum, and angular momentum but no mass.
Photons are particles and waves in quantum physics. They absorb, emit, and scatter stuff at the speed of light in a vacuum. Photons excite electrons in atoms and molecules, starting physical and chemical reactions.
E = hf, where E is the photon's energy, h is Planck's constant, and f is its frequency. Quantum physics relies on photons to comprehend light and matter interactions.
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What is the percent composition of Phosphorus in Li3PO3
Answer:
you will get 17.983 g of lithium for every 100 g of lithium phosphate.
Explanation:
69.7% is the percent by mass of Lithium in Li[tex]_3[/tex]PO[tex]_3[/tex]. A percent is obtained by multiplying the result by 100.
One approach to show the concentration for an element within a compound or component in a combination is as a mass percentage. The mass percentage is computed by dividing the total weight of the combination by the mass of each component and multiplying the result by 100%. The mass percent is calculated by dividing the mass that contains the compound and solute by the mass for the element or solute.
99.795g/mol = molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex]
6.94g/mol = molar mass of Li
mass percentage of Li=(molar mass of Li/molar mass of Li[tex]_3[/tex]PO[tex]_3[/tex])× 100
=(6.94/99.7)× 100
=69.7%
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In Step 5, you will calculate H+/OH– ratios for more extreme pH solutions. Find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 2. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C. What is the concentration of H+ ions at a pH = 2? mol/L What is the concentration of OH– ions at a pH = 2? mol/L What is the ratio of H+ ions to OH– ions at a pH = 2? : 1
The ratio of H⁺ ions to OH⁻ ions at a pH = 2 is 10¹⁰
Further explanationGiven
ph = 2
Required
The concentration of H⁺ and OH⁻ ions
Solution
The concentration of H⁺ ionspH=-log[H⁺]
2=-log[H⁺]
[H⁺]=10⁻²
The concentration of OH⁻ ionspH+pOH=14
pOH=14-2
pOH=12
pOH=-log[OH⁻]
12=-log[OH⁻]
[OH⁻]=10⁻¹²
The ratio of H⁺ ions to OH⁻ ions at a pH = 2[tex]\tt \dfrac{10^{-2}}{10^{-12}}=10^{10}[/tex]
Answer:
First one: 0.01
second one: 0.000000000001
third one: 10000000000
I've decided that i still want to have some orange juice
Answer:
Oh thats great..
But I hate juice :(
Why do rappers need umbrellas?
Maybe to not get rained on.
Hahhahahaha I ain't sure tho
Answer:
Fo' drizzle.
Explanation:
Someone solve b QUICK i’ll mark branliest
Answer :
(a) Reactant Mg is oxidized and reactant Fe is reduced.
(b) Reactant C is oxidized and reactant Cu is reduced.
Explanation :
As we know that a reactant is either reduced or oxidized in a chemical reaction.
If the oxidation state of an atom is decreases or gains electrons from reactant to product side then we can say that the reactant is reduced that means reduction.If the oxidation state of an atom is increases or loses electrons from reactant to product side then we can say that the reactant is oxidized that means oxidation.Part (a):
The given word equation of chemical reaction is:
Magnesium metal + Aqueous iron (III) sulphate → Iron metal + Aqueous magnesium sulphate
The balanced chemical equation of this word equation will be:
[tex]3Mg(s)+Fe_2(SO_4)_3(aq)\rightarrow 2Fe(s)+3MgSO_4(aq)[/tex]
In this reaction, the oxidation state of reactant Mg changes from (0) to (+2) that shows oxidation due to increase in oxidation state. So, we can say that Mg is oxidized.
And, the oxidation state of reactant Fe changes from (+3) to (0) that shows reduction due to decrease in oxidation state. So, we can say that Fe is reduced.
Part (b):
The given word equation of chemical reaction is:
Solid carbon + Solid copper oxide → Carbon dioxide gas + Copper metal
The balanced chemical equation of this word equation will be:
[tex]C(s)+2CuO(s)\rightarrow CO_2(g)+2Cu(s)[/tex]
In this reaction, the oxidation state of reactant C (carbon) changes from (0) to (+4) that shows oxidation due to increase in oxidation state. So, we can say that C is oxidized.
And, the oxidation state of reactant Cu changes from (+2) to (0) that shows reduction due to decrease in oxidation state. So, we can say that Cu is reduced.
Why did workers form labor unions?
Answer:
Labor unions were created in order to help the workers with work-related difficulties such as low pay, unsafe or unsanitary working conditions, long hours, and other situations. ... Sometimes the unions organized strikes in order to try to change the conditions of the workers.
Explanation:
Answer:
to speak with one voice
Explanation:
a p e x