Answer:
part of the skeleton that supports the structure of face and forms a cavity from bone.
Hope it help u.
Explanation:
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The barometric pressure measured outside an airplane at 3 km ( ft) was 524 mmHg. Calculate the pressure in kPa.
Answer:
69.8609 KPa.
Explanation:
The following data were obtained from the question:
Pressure (in mmHg) = 524 mmHg.
Pressure (in KPa) =?
Thus we can obtain the pressure in KPa as follow:
760 mmHg = 101.325 Kpa
Therefore,
524 mmHg = 524 mmHg × 101.325 KPa / 760 mmHg
524 mmHg = 69.8609 KPa
Thus, 524 mmHg is equivalent to 69.8609 KPa.
Which of the following indicates that an endothermic reaction has occurred?
Heat is released
Water is formed
Salt is produced
Temperature decreases
ive seen people say that its A but I don't think so because heat is released when its an exothermic reaction not an endothermic.
will mark brainiest if you get it right
Answer:
Temperature decreases
Explanation:
The correct answer that indicates that an endothermic reaction has occurred would be a reaction in which the temperature decreases.
An endothermic reaction is a reaction in which energy in the form of heat is absorbed from the surrounding. Hence, the final temperature of an endothermic reaction is usually lower than the initial temperature.
Endothermic reactions are the complete opposite of exothermic reactions in which heat is given off in the course of the reactions. Hence, the temperature of the reaction in exothermic reactions increases instead of decreasing.
In summary, a decrease in temperature of a reaction is an indication that heat has been absorbed during the course of the reaction and such a reaction is said to be endothermic.
Answer: Temperature Decreases
Explanation: Endothermic reaction is when heat is released meaning the temperature will decrease.
Calculate ΔHrxn for the following reaction:CH4(g)+4Cl2(g)→CCl4(g)+4HCl(g)Use the following reactions and given ΔH′s.C(s)+2H2(g)→CH4(g)ΔH=−74.6kJC(s)+2Cl2(g)→CCl4(g)ΔH=−95.7kJH2(g)+Cl2(g)→2HCl(g)ΔH=−184.6kJ
Answer:
ΔH= -390.3kJ
Explanation:
Using Hess's law, we can obtain ΔHrxn from the sum of related reactions.
Using:
(1) C(s) + 2H2(g) → CH4(g) ΔH=−74.6kJ
(2) C(s) + 2Cl2(g) → CCl4(g) ΔH=−95.7kJ
(3) H2(g) + Cl2(g) → 2HCl(g) ΔH=−184.6kJ
(2) - (1):
CH4(g) + C(s) + 2Cl2(g) → CCl4(g) + C(s) + 2H2(g)
CH4(g) + 2Cl2(g) → CCl4(g) + 2H2(g)
ΔH= -95.7kJ - (-74.6kJ) = -21.1kJ
This reaction + 2*(3):
2H2(g) + 2Cl2(g) + CH4(g) + 2Cl2(g) → CCl4(g) + 2H2(g) +4HCl(g)
CH4(g) + 4Cl2(g) → CCl4(g) + 4HCl(g)
ΔH= -21.1kJ + 2*-184.6kJ
ΔH= -390.3kJAdd oxidation numbers to the following reaction: 2 H3PO4 (aq) + 2 Cr(s) → 2 CrPO4 (aq) + 3 H2(g). Identify the atom that is oxidized and identify the oxidizing agent.
The atom that is oxidized : Cr
The oxidizing agent : H₃PO₄
Further explanationReaction
2 H₃PO₄ (aq) + 2Cr(s) → 2 CrPO₄ (aq) + 3H₂(g)
Atoms undergoing a reduction reaction (decrease in oxidation number) and an oxidation reaction (increase in oxidation number)
Reduction (+1 to 0)H⁺(in H₃PO₄) =+1
H₂=0
Oxidation (0 to +3)Cr = 0
Cr³⁺(in CrPO₄ )
the oxidizing agent.⇒which undergoes a reduction reaction and oxidizes another compound/element : H₃PO₄
BaO2 is a peroxide. Why?
Answer:
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What would happen if you shone a lazer light into a glass of water?
Answer:
Reflection/change of direction
Explanation:
When the light of the laser hits the glass of water, it reflects and goes another direction. It's basically just a change of direction. The light is mostly in the glass of water and just some reflecting off of it.
A gas sample in a balloon contains 4.0 moles of gas at a particular pressure, volume and temperature. If your balloon springs a leak and the volume decreases to 1/2 of the original amount before you can plug the leak, how many moles of gas have you lost (temperature and pressure remain the same)?
Answer:
Explanation:
When volume of gas is V , pressure is P and temperature is T , if n be number of moles of gas
PV / RT = n , R is universal gas constant .
When volume becomes .5 V , pressure P and temperature T
number of moles = Px .5 V / RT = .5 PV / RT = .5 n
Number of moles of gas becomes half .
so 4 moles becomes 2 moles
No of moles lost = 4 - 2 = 2 moles.
Calculate the mass percent composition of iron for the third one of these iron ores.
Iron is mined from the earth as iron ore. Common ores include Fe2O3 (hematite), Fe3O4 (magnetite), and FeCO3 (siderite).
Answer:
[tex]\% Fe=48.2\%[/tex]
Explanation:
Hello!
In this case, since the percent composition of an element in a compound is given by:
[tex]\% i =\frac{z_i*m_i}{MM}*100\%[/tex]
Whereas i represent the element in the compound for which we want compute the mass percent. As required for siderite, FeCO3 whose molar mass is 115.854 g/mol, and knowing there is one iron atom there with an atomic mass od 55.85 g/mol, the mass percent of iron there is:
[tex]\% Fe=\frac{1*55.85}{115.854}*100\%\\\\\% Fe=48.2\%[/tex]
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The pressure of a 5.0 L sample of gas changes from 3.0 atm to 10.0 atm while the temperature remains constant. What is the gas’s new volume?
Answer:
The answer is 1.5 LExplanation:
The new volume can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
From the question we have
[tex]V_2 = \frac{5 \times 3}{10} = \frac{15}{10} = \frac{3}{5} \\ [/tex]
We have the final answer as
1.5 LHope this helps you
List any three quantum numbers that describe an electron in an atom and state the relationship between any of the two
Explanation:
To completely describe an electron in an atom, four quantum numbers are needed: energy (n), angular momentum (ℓ), magnetic moment (mℓ), and spin (ms).
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A student needs to use the metric system while measuring the length of a box. Which units should he use?
AWNSER FAST PLEASEEE
Answer:
Centimeters or milimeters.
Explanation:
The answer depends on the size of the box.
The metric system base unit for length is the meter. Centimeters and milimeters are thus also part of the metric system.
If the box is a "regular-sized" box that we use to put stuff in (books, presents, etc), then centimeters would be the most appropiate.
If we're talking about those tiny boxes that are printed on paper (for example in some notebooks) then milimeters would be the most appropiate.
Answer:
Centimeters
Explanation:
Consider the following reaction:2 HgCl2(aq) + C2O42-(aq) 2 Cl-(aq) + 2 CO2(g) + Hg2Cl2(s)(a) The rate law for this reaction is first order in HgCl2(aq) and second order in C2O42-(aq). What is the rate law for this reaction?Rate = k [HgCl2(aq)] [C2O42-(aq)]Rate = k [HgCl2(aq)]2 [C2O42-(aq)]Rate = k [HgCl2(aq)] [C2O42-(aq)]2Rate = k [HgCl2(aq)]2 [C2O42-(aq)]2Rate = k [HgCl2(aq)] [C2O42-(aq)]3Rate = k [HgCl2(aq)]4 [C2O42-(aq)](b) If the rate constant for this reaction at a certain temperature is 0.0169, what is the reaction rate when [HgCl2(aq)] = 0.158 M and [C2O42-(aq)] = 0.202 M?Rate = M/s.(c) What is the reaction rate when the concentration of HgCl2(aq) is doubled, to 0.316 M while the concentration of C2O42-(aq) is 0.202 M?Rate = M/s
Answer:
b
Explanation:
A crow flies 100 meters east in 5 minutes. What is the crow’s velocity?
Answer: 20 m/min east
Explanation: The speed is distance divided by time
distance between start-point and end-point = 100 meters
time to cover the distance = 5 minutes
100 m ÷ 5 min = 20 m/min east
you have to add east since velocity is the measure of speed and direction and your answer needs to include the direction
Which order system shows the levels of organization from largest to smallest
organism, organ system cell organ tissue
organism tissue organ system organ cell
organism organ organ system cell tissue
organism organ system organ tissue cell
Answer:
3) organism organ system organ tissue cell
Explanation:
1. Is it possible to distinguish DNA and RNA structures by using Bial’s Test? Explain.
2. What are the functions of orcinol and FeCl3 in Bial’s Test.
Answer:
yes and thats all i know
Explanation:
The nucleus of an atom is made up of which of the following combinations of particles?
Answer: Atoms of different elements are found to have different number of protons, neutrons, and electrons. To distinguish one atom from another or to classify the various atoms, a number which indicates the number of protons in the nucleus of a given atom, is assigned to the atoms of each identified element. This number is known as the atomic number of the element. The atomic numbers for some of the elements which are associated with the study of semiconductors are given in the following table.
Explanation:
Element Symbol Atomic Number
Silicon Si 14
Germanium Ge 32
Arsenic As 33
Antimony Sb 51
Indium In 49
Gallium Ga 31
Boron B 5
Answer:
[tex]\boxed {\boxed {\sf Protons \ and \ neutrons}}[/tex]
Explanation:
The atom is made up of two main parts: the nucleus and the electron cloud.
The nucleus is the center and has two subatomic particles: the protons (positive charge) and the neutrons (no/neutral charge). The nucleus as a whole has a positive charge, since the neutrons don't provide a charge.
The electron cloud surrounds the nucleus and houses the negatively charged electrons in a "cloud" of energy levels.
So, the nucleus of the atom is made up of protons and neutrons.
How to make the solar oven using the following materials
-pizza box
-aluminium foil
-mirror
-hot glue
-chopstick
Answer:
hot glue
Explanation:
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How much water must be added to 424 mL of 0.189 M HCl to produce a 0.140 M solution?
Answer:
Volume of water added = 148.4 mL
Explanation:
Given data:
Initial volume = 424 mL
Initial molarity = 0.189 M
Final molarity = 0.140 M
Volume of water added = ?
Solution:
Formula:
M₁V₁ = M₂V₂
0.189 M×424 mL = 0.140 M×V₂
V₂ = 0.189 M×424 mL /0.140 M
V₂ = 80.136 M.mL / 0.140 M
V₂ = 572.4 mL
Final volume of solution is 572.4 mL.
Volume of water added = Final volume - initial volume
Volume of water added = 572.4 mL - 424 mL
Volume of water added = 148.4 mL
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5. Which two body systems work together to bring oxygen into the body's cells
and take carbon dioxide away?
A. Nervous and endocrine
B. Respiratory and digestive
C. Respiratory and circulatory
D. Muscular and skeletal
Answer:
C
Explanation:
the respiratory system and the circulatory system work closely together to deliver oxygen to cells and to get rid of the carbon dioxide the cells produce. The circulatory system picks up oxygen in the lungs and drops it off in the tissues, then performs the reverse service for carbon dioxide.
The two-body systems that work together to bring oxygen to the body's cells and remove carbon dioxide are the RESPIRATORY system and CIRCULATORY system (Option C).
The red blood cells of the circulatory system transport oxygen from the lungs and other nutrients to all the cells of the body, which are required to carry out a process called cellular respiration.
Moreover, carbon dioxide is also transported in the red blood cells to the lungs in the opposite direction.
The alveoli in the lungs of the respiratory system function to absorb oxygen from the air through the process of inhalation and subsequently eliminate carbon dioxide through exhalation.
In conclusion, the two-body systems that work together to bring oxygen to the body's cells and remove carbon dioxide are the RESPIRATORY system and CIRCULATORY system (Option C).
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Why are the sublevels within a principal level split into different energies for multi-electron atoms but not for hydrogen atom?
Answer:
Kindly check the explanation section.
Explanation:
Hydrogen in the periodic chart/table is the first element on the periodic table with binding energy of 0.000± 0.0000 keV, Isotopic mass of 1.007825 u, one or single proton and a spin value of half(1/2).
The first thing to note for the fact that hydrogen's sublevels within a principal level does not split into seperate or different energies is that THERE IS A VACANT GROUND STATE IN HYDROGEN ATOM. With this, it makes it impossible for the electrons that are inside to get infiltrated which is the case with the atoms with multielectron.
NB: Penetration is done by electrons outside.
Heavier compounds tend to have higher boiling points. However, sulphur dichloride (Mr= 103.1 gmol-1) and sulphur hexafluoride (Mr = 146.1 g mol-1) have the boiling point of 59 °C and -50.8 °C respectively. Explain this phenomenon.
The diagram shows water in a graduated cylinders. Graduated cylinder B has 30 mL of water.
What is this statement and example of?
(4 Points)
Prediction
A theory
An observation
A hypothesis
write the formular of the compound formed when element D and oxygen react together
Answer:
D oxide
Explanation:
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What element produced the unknown emission spectrum?
Answer:
The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.
Luca made the following chart for Earth’s four basic movements. What needs to be correct on his chart
Answer:
The solar system speed and Milky Way speed should be switched
Explanation:
Answer:
Explanation:
The solar system speed and Milky Way speed should be switched
Write a balanced half-reaction describing the oxidation of aqueous iodide anions to gaseous diiodine.
Answer:
I might be a little late but in case anyone in the future needs it the answer is 2I^-(aq) ---> I_2(g)+2e^-
The balanced half reaction describing the oxidation of aqueous iodide anions to gaseous diiodine is;
2I-(aq). ==>. I2(g) + 2e-Definition:
Oxidation as determined by oxidation Numbers simply refers to an increase in oxidation number.
In essence, the chemical reaction above involves the increase in oxidation number of Iodine, I from -1 to 0.
The half reaction is thus so, because gaseous diiodide is a diatomic element.
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what is Acid and any type of acid
Answer:
Acid is the substance which gives H+ ions when dissolved in an aqueous solution and tastes sour.
Types of acid
Strong acidWeak acidAnswer:
An acid is a molecule or ion capable of donating a proton (hydrogen ion H+) or, alternatively, capable of forming a covalent bond with an electron pair.
Explanation:
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in which beakers are the particles moving the most slowly
Why do scientists' study and synthesize new transuranium elements in the laboratory?
Explanation:
Nuclear structure and stability
Although the decay properties of the transuranium elements are important with regard to the potential application of the elements, these elements have been studied largely to develop a fundamental understanding of nuclear reactions and nuclear and atomic structure.