Answer:
helium
Explanation:
HELP I WILL MARK BRAINLIST
I HAVE 10 MINUTES
Which phrase correctly describes the effect of pressure on the solubility of a gas in a liquid?
1) proportional to the square root of the pressure of the gas above the liquid
2) directly proportional to the pressure of the gas above the liquid
3) inversely proportional to the pressure of the gas above the liquid
4) unrelated to the pressure of the gas above the liquid
Answer:
Answer is 2
Explanation:
directly pro
Oxidation unit test
Please help ASAP!!!
Which statement correctly describes the oxidation number of the manganese atom (Mn) in Mnl2 and MnO2?
O Manganese has an oxidation number of +4 in Mnl2 and +2 in MnO2.
o Manganese has an oxidation number of +2 in Mnl2 and +4 in MnO2.
o Manganese has an oxidation number of +4 in both Mnl2 and MnO2.
Manganese has an oxidation number of +2 in both Mnl2 and MnO2.
In this case, according to the given information about the oxidation numbers and the compounds given, it turns out possible to figure out the oxidation number of manganese in both MnI2, manganese (II) iodide and MnO2, manganese (IV) oxide, by using the concept of charge balance.
Thus, we can define the oxidation state of iodine and oxygen as -1 and -2, respectively, since the former needs one electron to complete the octet and the latter, two of them.
Next, we can write the following [tex]x[/tex], since manganese has five oxidation states, and it is necessary to calculate the appropriate ones:
[tex]Mn^xI_2^-\\\\Mn ^xO_2^{-2}[/tex]
Next, we multiply each anion's oxidation number by the subscript, to obtain the following:
[tex]Mn^xI_2^-\rightarrow x-2=0;x=+2\\\\Mn ^xO_2^{-2}\rightarrow x-4=0;x=+4[/tex]
Thus, the correct choice is Manganese has an oxidation number of +2 in Mnl2 and +4 in MnO2.
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https://brainly.com/question/15167411 https://brainly.com/question/6710925Is there more than one possible model that could be inferred from Rutherford’s data?
Rutherford proposed the nuclear model of atom. The only one model which can be inferred from this model is nucleus with protons and revolving electrons around.
What is Rutherford model?Rutherford proposed some aspects of atomic structure based on his gold foil experiment. He discovered that the alpha ray is scattering from foil by the repulsion it experienced from the metal.
This results lead to the discovery of positively charged particles in atom latter called as protons. Rutherford proposed that theses protons are located inside the nucleus and the electrons are revolving around the nucleus.
Latter Niels Bohr his student interpreted the nuclear model of Rutherford with quantum mechanics and theory of max planck and he proposed the equations for the determination of energy and momentum of electrons and the radius of atom.
Therefore, no other inferences except the presence of protons and revolving electrons can be obtained from Rutherford's model of atom.
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If you have an aqueous solution that is 13.5 % Na3PO4 by mass, what is the molality of Na3PO4 in the solution?
Considering the definition of percentage by mass and molality, the molality of Na₃PO₄ in the solution is 0.948 [tex]\frac{moles}{kg}[/tex].
Percentage by mass
The percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.
In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.
The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:
[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]
MolalityMolality is the ratio of the number of moles of any dissolved solute to kilograms of solvent.
The Molality of a solution is determined by the expression:
[tex]molality=\frac{number of moles of solute}{kilograms of solvent}[/tex]
This caseConsidering 100 grams as a sample of the solution, then the value of the percentage of concentration given indicates that 13.5 g correspond to Na₃PO₄.
Remember that percent concentration by mass is calculated using the mass of solute and the mass of the solution, which includes both the solute and the solvent. Then:
mass solution= mass solute + mass solvent
100 g= 13.5 g + mass solvent
100 g - 13.5 g= mass solvent
86.5 g= mass solvent
Then, you know:
number of moles of solvent= [tex]13.5 gramsx\frac{1 mole}{163.94 grams} =0.082 moles[/tex] being 163.94 [tex]\frac{grams}{mole}[/tex]the molar mass of Na₃PO₄, this is the amount of mass a substance contains in one mole.mass of solvent= 86.5 grams= 0.0865 kg (being 1000 g= 1 kg)Then, replacing in the definition of molality:
[tex]molality=\frac{0.082 moles}{0.0865 kg}[/tex]
Solving:
molality= 0.948 [tex]\frac{moles}{kg}[/tex]
Finally, the molality of Na₃PO₄ in the solution is 0.948 [tex]\frac{moles}{kg}[/tex].
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mass percentage:brainly.com/question/19168984?referrer=searchResultsbrainly.com/question/18646836?referrer=searchResultshttps://brainly.com/question/20037730?referrer=searchResultshttps://brainly.com/question/25148948molalitybrainly.com/question/20366625?referrer=searchResultsbrainly.com/question/4580605?referrer=searchResultsMilkweed contains a poison known as cardenolides. Monarch butterflies eat the milkweed plant and hold on to this toxic compound. The chemical formula for cardenolides is shown below.
CH18C20H15CHCO2
How many atoms of each element are in one molecule of cardenolides?
A)
34 carbon atoms, 43 hydrogen atoms, and 2 oxygen atoms
B)
42 carbon atoms, 23 hydrogen atoms, and 2 oxygen atoms
C)
20 carbon atoms, 33 hydrogen atoms, and 2 oxygen atoms
D)
23 carbon atoms, 34 hydrogen atoms, and 2 oxygen atoms
Answer:
the answer is D) 23 carbon atoms, 34 hydrogen atoms, and 2 oxygen atoms
Explanation:
i took the test and got a 100%
Glucose can be found in foods like honey. What happens to glucose in the body?
OA. It goes through chemical reactions with carbon dioxide, which provides oxygen and energy for cells.
ОВ.
It goes through a physical change in the cell's nucleus to produce oxygen.
OC.
It uses carbon dioxide in the cell's nucleus to produce a larger sugar molecule.
OD.
It goes through chemical reactions with oxygen, which forms new molecules and provides energy for cells. Will Give Brainliest No
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Answer:It goes through chemical reactions with oxygen, which forms new molecules and provides energy for cells.
how is waste removed from the body
Waste is removed from the body in various ways. Kidneys filter out metabolic waste, excess fluid and eliminate it in the form of urine. Lungs exhale CO2 from the deoxygenated blood. The undigested solid waste is egested out from the large intestine. Excretion is the process of removing wastes and excess water from the body. It is one of the major ways the body maintains homeostasis. Organs of excretion make up the excretory system. They include the kidneys, large intestine, liver, skin, and lungs.
Calculate the second ionization energy of the metal M (?Hion2� in kJ/mol) using the following data:
Lattice enthalpy of MO(s), ?Hl� = -2383 kJ/mol
Bond dissociation enthalpy of O2(g) = +498 kJ/mol
First electron affinity of O = -141 kJ/mol
Second electron affinity of O = +744 kJ/mol
Enthalpy of sublimation of M = + 130 kJ/mol
First ionization energy of M = + 267 kJ/mol
Standard enthalpy of formation of MO(s), ?Hf� = -307 kJ/mol
From the information provided in the question, the second ionization energy of the metal is 578 kJ/mol.
From the question, we have the following information;
Lattice enthalpy of MO(s) = -2383 kJ/mol
Bond dissociation enthalpy of O2(g) = +498 kJ/mol
First electron affinity of O = -141 kJ/mol
Second electron affinity of O = +744 kJ/mol
First ionization energy of M = + 267 kJ/mol
Heat of sublimation of M = + 130 kJ/mol
Standard enthalpy of formation of MO(s) = -307 kJ/mol
Using Hess law of constant heat summation;
ΔHf = ΔHs + BE + ∑IE + ∑EA + U
ΔHs = Heat of sublimation of metal
ΔHf = Heat of formation MO
BE = Bond energy of O2
∑EA = sum of electron affinities of Oxygen
∑IE = Sum of the ionization energies of M
U = Lattice energy of MO
Let the second ionization energy be x
Substituting values;
(-307) = 130 + 498 + (267 + x) + 603 + (-2383)
(-307) = -885 + x
-x = -885 + 307
-x = -578
x = 578 kJ/mol
The second ionization energy of the metal is 578 kJ/mol.
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For the reaction C + O2 = CO2, if 3 grams of carbon react with the oxygen, how many grams of carbon dioxide are produced?
Name the following Type 1 compounds:
1. Naci
2. KI
3. Cas
4. CsBr
5. Mgo
6. CSF
7. AICI:
8. Mg2
9. Rb20
10.Sr12
11.KAS
Answer:
44
Explanation:
list atleast two examples of Arrhenius acids?
Answer:
HCl (hydrochloric acid) and H2SO4 (sulphuric acid)
I hope it helps.
Magnesium has a density of 1.74 g/cm3. What is the volume of 58.6 g of Mg?
Answer:
1 kg = 1000 g
58.6=58,600g
Explanation:
10. Select the more polar bond in each of the following pairs: a) C and N or C and o b) N and F or N and O.
Three test tubes contain aqueous hydrogen sulfide, aqueous sulfur-dioxide and Lugol reagent. By mixing any two of the three test tubes, identify their contents. Explain, stating reasons, how you arrive at your conclusions. Write equations whenever applicable.
Answer:
Initial rate experiments
The simplest initial rate experiments involve measuring the time taken for some recognizable event to happen early in a reaction. This could be the time required for 5 cm3 of gas to be produced, for a small, measurable amount of precipitate to form, or for a dramatic color change to occur. Examples of these three indicators are discussed below.
The concentration of one of the components of the reaction could be changed, holding everything else constant: the concentrations of other reactants, the total volume of the solution and the temperature. The time required for the event to occur is then measured. This process is repeated for a range of concentrations of the substance of interest. A reasonably wide range of concentrations must be measured.This process could be repeated by altering a different property.
Explanation:
I don't think so if this is the answer. if not ok sorry
17.
In the reaction N2 + 3H2 → 2NH3 how many moles of ammonia will be produced from 1.30 mol
of hydrogen and excess nitrogen?
According to the equation given, we have N2 + 3H2 → 2NH3.
Therefore, to determine the moles of NH3 we have to do the following-
1.3 mol H2 × 2 mol NH3 / 3 mol H2 = 0.87 mol
Answer: .87 moles of NH3 are produced from 1.3 moles of H2.
I hope this helps!
The sun, fire, lightnings and fireflies are all
Answer:
Natural source of light
Explanation:
Please Mark Me Brainlest Me#CarryOnLearningCan someone help me out with this question and explain me the answer too!!! Please
Answer:
sorry i dont know
Explanation:
classify each of the statements about gases as true or false. oxygen molecules at 25 celsius are moving faster than oxygen
Since gas molecules average velocity depends on temperature, oxygen molecules at 25°C are moving faster than oxygen molecules at 0 °C.
According to the kinetic theory of gases, the molecules of a gas are in constant random motion and collide frequently with each other and the walls of the container.
The average speed of gas molecules depends on temperature and molar mass as shown by the relation;
vrms = √3RT/M
The following statement are true among the options provided;
Oxygen molecules at 25°C are moving faster than oxygen molecules at 0 °C Gases exert pressure by colliding with container wallsThe following are false among the options provided;
All hydrogen molecules are moving with the same velocityNitrogen gas exerts more pressure than hydrogen gas because nitrogen molecules are heavier than hydrogen molecules. Nitrogen molecules remain suspended in the atmosphere because they are not attracted to Earth by gravitational forces.Learn more: https://brainly.com/question/6505878
Thin-layer chromatography explain ?????
Answer:
Explanation:
Thin-layer chromatography (TLC) is a chromatography technique used to separate non-volatile mixtures. ... After the sample has been applied on the plate, a solvent or solvent mixture (known as the mobile phase) is drawn up the plate via capillary action.
The process of returning mines to their original state is called ________________________.
Answer:
Mine Reclamation.Explanation:
The process of returning mines to their original state is called Mine Reclamation. HOPE THIS HELPS :)a 13.5 g sample of zinc(zn) heated from 24.2 degrees celsius to 83.6 degrees celsius that absorbs 312j of heat? use specific heat
Explanation:
83.6-24.2= 59.4 which is the change in heat
plate tectonics-1.gif
What is the above image a representation of?
Answer:
Subduction Process where the oceanic plate subducted under the continental plates because it denser than the Continental plate.
Which two substances are reactants in the chemical reactions of cellular respiration?
Answer:
The answer is A and C.
Explanation:
The reactants in the process of cellular respiration are oxygen and glucose, respectively. It is ATP that serves as the primary product of cellular respiration, with carbon dioxide and water serving as waste products.
Sugar is a glucose.
Oxygen and glucose are the two substances that are reactants in the chemical reactions of cellular respiration. Therefore, the correct options are options A, C.
What is cellular respiration?Through the process of cellular respiration, organisms mix oxygen with food molecules, directing the chemical energy contained in these substances towards life-sustaining processes while excreting carbon dioxide and water as waste. Foods are broken down by microorganisms that do not require oxygen in a process known as fermentation.
Adenosine triphosphate (ATP), an energy-rich compound that absorbs the chemical energy generated by the decomposition of food molecules then releases it to power other cellular functions, is one goal of the breakdown of foodstuffs. ATP is created when the energy found inside chemical bonds is converted from one form to another. Oxygen and glucose are the two substances that are reactants in the chemical reactions of cellular respiration.
Therefore, the correct options are options A, C.
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What identifies the number of protons in the nucleus of an atom?
Answer: Atomic number
Explanation:
I hope this helps you!
how is atom and molecules related to our sense of smell?
Answer:
Atoms themselves do not have a smell. Molecules do.
Explanation:
What happens is that particular molecules bind to receptors in our nose, activating nerves, that then send signals to our brain, which we then interpret and perceive as “smells”. Different molecules bind to different receptors, which is why we can perceive a number of different smells
a. Calculate the change in enthalpy when 20.0 grams of aluminum metal is heated from 298 K to 573 K at constant pressure of 1 atm.
b. Calculate the change in enthalpy when 20.0 grams of metallic lead is taken through the same process. In both cases assume the heat capacity values predicted by equipartition are valid through the temperature range stated.
A pan containing 40 grams of water was allowed to cool from a temperature of 91.0 °C. If the amount of heat released is 1,300 joules, what is the approximate final temperature of the water? 74 °C 78 °C 81 °C 83 °C
Answer:
d. 83 °c
Explanation:
Answer:
D. 83 c
Explanation:
took the test
Find the volume of 0.170 M sulfuric acid necessary to react completely with 72.2 g sodium hydroxide.
The volume of sulphuric acid, H₂SO₄ needed for the complete reaction with 72.2 g of sodium hydroxide, NaOH is 5.31 L
We'll begin by calculating the number of mole in 72.2 g of NaOH. This can be obtained as follow:
Mass of NaOH = 72.2 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mole of NaOH =?Mole = mass / molar mass
Mole of NaOH = 72.2 / 40
Mole of NaOH = 1.805 mole Next, we shall determine the number of mole of H₂SO₄ needed to react with 1.805 mole of NaOH.2NaOH + H₂SO₄ —> Na₂SO₄ + 2H₂O
From the balanced equation above,
2 moles of NaOH reacted with 1 mole of H₂SO₄.
Therefore,
1.805 mole of NaOH will react with = 1.805 / 2 = 0.9025 mole of H₂SO₄.
Finally, we shall determine the volume of H₂SO₄.Mole of H₂SO₄ = 0.9025 mole
Molarity of H₂SO₄ = 0.170 M
Volume of H₂SO₄ =?Volume = mole / Molarity
Volume of H₂SO₄ = 0.9025 / 0.170
Volume of H₂SO₄ = 5.31 LThus, the volume of H₂SO₄ needed for the reaction is 5.31 L
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Which of the following describes how air resistance affects the motion of a falling object?
Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.
Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.
Air resistance may change the direction of a falling object but does not affect its speed.
Air resistance may change the direction of a falling object but does not affect its speed.
Air resistance works with gravity to pull a falling object towards the Earth.
Air resistance works with gravity to pull a falling object towards the Earth.
Air resistance opposes the force of gravity and causes an object to reach terminal velocity.
Air resistance opposes the force of gravity and causes an object to reach terminal velocity.
Air resistance opposes the gravity in a falling object hence the object loses speed once it reaches terminal velocity.
According to the experiment of Galileo, in the absence of air resistance, all objects that are thrown down from the same height will hit the ground at he same time due to the effect of gravity.
We know that the air resistance makes the acceleration of object to become less than the acceleration due to gravity. So, air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.
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Answer:
The answer is D - Air resistance opposes the force of gravity and causes falling objects to lose speed once they reach terminal velocity.
Ill explain why -, for example ,
When the paper is smooth, it exposes a large surface to the air beneath it which slows its descent. Once it is crumpled, the surface which comes in contact with the air is much smaller, allowing it to fall much faster. At first, you probably thought the book would touch the ground first since it is heavier However, once the piece of paper was crumpled, they hit the ground at the same time! Funny, since it is the same piece of paper and the book is still heavier. It all comes down to form. I hope this helped u with the test !!
Radio waves bounce off of _____________ before returning to Earth
Answer: ionosphere
Explanation: First it bounces off a top layer of the atmosphere called the ionosphere, then it bounces back to the Earth (this is reflection. It then bounces up again to the ionosphere, and continues bouncing back again until it reaches the radio receiver. This is called a skywave, which works around 3 to 30 MHz.