If a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
Eclipse is said to occur when one of the heavenly bodies casts a shadow on another heavenly body causing it to be partly visible or completely invisible. When the earth comes between the sun and the moon, a lunar eclipse is said to occur.
When a lunar eclipse occurs, the moon may be partly visible or completely invisible. Therefore, if a student notices that one-quarter of the moon is visible, a lunar eclipse has taken place.
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Can someone help me out with this question and explain me the answer too!!! Please
Answer:
sorry i dont know
Explanation:
5. Select the answer for both questions
Answer:
engey
Explanation:
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.
How many grams of steam at 100 °C would be required to raise the temperature
of 47.6 g solid benzene (CH) from 5.5 °C to 30.0 °C? Assume that heat is only
transferred from the steam (and not liquid water) and that the steam/water and
benzene are separated by a glass wall and do not mix. (The melting point of ben-
zene is 5.5 °C; AHus for benzene is 9.87 kJ/mol; specific heat for benzene is 1.63
J/g• °C; AH for steam at 100 °C is 40.7 kJ/mol.)
vap
The mass of steam required to raise the temperature of water is 3.5 g.
The given parameters;
mass of the benzene, = 47.6initial temperature of the benzene, = 5.5 ⁰Cfinal temperature of the benzene = 30 ⁰CThe molar mass of Benzene = 78.11 g/mol
The molar mass of water = 18 g/mol
The number of moles of the Benzene is calculated as follows;
[tex]n = \frac{47.6}{78.11} = 0.61 \ mole[/tex]
The mass of steam required is calculated as follows;
heat lost by steam = heat absorbed by benzene
[tex]\frac{m}{18} \times 40.7 \times 10^3 = 47.6(1.63)(30-5.5) \ + \ 0.61 \times 9.87 \times 10^3\\\\2261.11 m = 7921.61\\\\m = \frac{7921.61}{2261.11} \\\\m = 3.5 \ g[/tex]
Thus, the mass of steam required to raise the temperature of water is 3.5 g.
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Milkweed 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%
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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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
5. What is the systemic name for the following structure?
Answer:
You are not showing the question, but I believe the answer is cis-3,4-dimethyl-3-hexene.
Explanation:
since the substituents are on same side, it call cis. Followed by the name.
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.
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
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 :)The sun, fire, lightnings and fireflies are all
Answer:
Natural source of light
Explanation:
Please Mark Me Brainlest Me#CarryOnLearningWhat identifies the number of protons in the nucleus of an atom?
Answer: Atomic number
Explanation:
I hope this helps you!
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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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!
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 !!
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
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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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/671092510. 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.
9. Calculate the pOH and pH of a 0.35 M solution of the weak acid HCN.
Ka HCN = 4.8 x 10-10
Answer:
=0.35hcn20 4.7 x hcn(poh) =hcnty sa pointd
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.
list atleast two examples of Arrhenius acids?
Answer:
HCl (hydrochloric acid) and H2SO4 (sulphuric acid)
I hope it helps.
please help asap!!!!!!!
Answer:
c) single bonds, double bonds, carbon atoms and hydrogen atoms
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.
answer this please........
2. Cells are the_____________ life units on this plane
Answer:
Cell are the smallest life units on this planet
Explanation:
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:
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
Links
Answer:It goes through chemical reactions with oxygen, which forms new molecules and provides energy for cells.
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