Answer:.1 kJ = 1000 J and 1J=0.24cal
----->78.9kJ=1000x78.9x0.24=18936cal
Explanation:
This is the unit regulated by the scientific community and they follow the formula that they prove
use the density formula to solve the following problems. a sample of a substance has a volume of 60.5mL and a density of 1.20mL. What is the mass of the sample?
Answer:
mass of substance =50.4 g
Explanation:
Using the density formula;
Density = mass of substance / volume of substance
Therefore, making mass subject of the density formula,
mass of substance = volume of substance / density of substance
volume of substance = 60.5 mL, density = 1.20 g/mL ( since common units of density is either g/cm³ or g/mL)
mass of the substance = 60.5 mL / 1.20 g/mL
mass of substance = 50.4 g
What is the mass of 2.86 moles of silver (Ag)?
Answer:
308,4796 g.
Explanation:
1 mol equals to 107,86 g, now times 2,86 mol, 308,4796 g.
Which best explains how fiber-optic technology benefits the field of medicine?
O It allows doctors to view internal body structures to help them diagnose illnesses.
O It helps surgeons make more accurate repairs to broken blood vessels.
O It allows doctors to magnify cells so they can identify unhealthy cells that cause cancer.
O It helps surgeons make cuts that are smaller and less painful than traditional methods.
Answer:
A. It allows doctors to view internal body structures to help them diagnose illness.
Explanation:
The statement, that describes fiber-optic technology benefits the field of medicine is "it allows doctors to view internal body structures to help them diagnose illnesses."
What is fiber-optic technology?Fiber optics is a technology that transmits information as light pulses across great distances using strands of glass or plastic fibre. Fiber-optic cables use light pulses that travel quickly to convey data.
Internal organs and tissue can be viewed through bodily orifices because to the flexible yet hard multi-fibers. Endoscopes are used by doctors to explore symptoms such as nausea and gastrointestinal pain, confirm diagnosis through biopsies, and provide medical therapy.
Medical fibre optics are an important medical technology that is employed in a variety of medical professions. They are chemically inert, sterile, malleable, and non-toxic to the human body. Fiber optic technology enables surgeons to repair organs, diagnose joint problems, and remove sick tissues, resulting in a faster recovery period for the patient than more intrusive surgical approaches.
Hence the correct answer is it allows doctors to view internal body structures to help them diagnose illnesses.
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Why can't scientific method always be used to solve social, political, ethical, and economic problems?
Answer:
In fact, science helps a lot for social, political, ethical, and economic problems. Your question is just to deny that science is not helping your life and you have no evidence to support what you say.
Explanation:
15 x 10^2) + (5.2 x 10^5)
Explanation:
(15 × 10^2) =1500.
(5.2 ×10^5)=520000.
(1500)+(520000).
=518500 .
When a change in a physical property is observed, Select the correct answer below: it could be because of a physical change. it must be because of a chemical change. it must be because of a chemical change and a physical change. it could be caused by a change that is considered both physical and chemical.
Answer:
It could be because of a physical change.
Explanation:
A physical change affects a substance's physical properties, and a chemical change affects its chemical properties.
For the reaction: CO(g) + H2O(g) ⇌ CO2(g) + H2(g) the value of Kc is 1.845 at a specific temperature. We place 0.500mol CO and 0.500mol H2O in a 1.00L container at this temperature and allow the reaction to reach equilibrium. Determine the equilibrium concentration of all species present in the container.
Answer:
Explanation:
In the equilibrium:
CO(g) + H₂O(g) ⇄ CO₂(g) + H₂(g)
Kc is:
Kc = 1.845 = [CO₂] [H₂] / [CO] [H₂O]
Where [] are equilibrium concentrations of each species
Initial concentrations:
[CO] = 0.500mol / 1.00L = 0.500M
[H₂O] = 0.500mol / 1.00L = 0.500M
In equilibrium, concentrations will be:
[CO] = 0.500M - X
[H₂O] = 0.500M - X
[CO₂] = X
[H₂] = X
Where X is reaction coordinate. The amount of reactant that reacts producing products.
Replacing in Kc expression:
1.845 = [CO₂] [H₂] / [CO] [H₂O]
1.845 = [X] [X] / [0.500M - X] [0.500M - X]
1.845 = X² / X² - X + 0.25
1.845X² - 1.845X + 0.46125 = X²
0.845X² - 1.845X + 0.46125 = 0
Solving for X:
X = 0.288M; Right solution
X = 1.9M; False solution: Produce negative concentrations.
Replacing, equilibrium concentrations are:
[CO] = 0.500M - X = 0.212M
[H₂O] = 0.500M - X = 0.212M
[CO₂] = X = 0.288M
[H₂] = X = 0.288M
iron is a metal that rusts in the presence of oxygen and water. mild steel is used for ...1... and is prevented from rusting by ...2...chemistry igcse
Answer and Explanation:
Used as a construction frame material and for bending metal works because they are rigid and strong.Galvanising or coating the surface would prevent rusting.N.B.: Mild steel is steel that has low carbon content, also called carbon steel.
I hope this explanation was helpful.
Answer:
car bodiespaintingExplanation:
Mild steel is used in making car body parts because it is malleablePainting mild steel prevents moisture and oxygen from reaching the metalWhere is altitude measured in meters? How did this affect the MD-11?
Answer:
China, Mongolia, Russia, and North Korea. They were told to fly at 1400 meters but they flew at 1500 feet making them crash.
Explanation:
How could the survivors about starting a fire?
What is fire?Describe it.
What makes a fire hot?
Answer:
The ancient Greeks believed that fire was one the four basic elements that composed all things in the universe. In the mythology of virtually every culture, fire is a sacred substance that gives life or power. Fire is not, in fact, a substance. When you gaze at the leaping flames of a campfire, you’re observing not an object, but a process – a chemical reaction. It’s the same chemical reaction that occurs when a cut apple left on the counter turns brown, when silver tarnishes or when an iron nail rusts.
That process is oxidation: combining oxygen with another substance. The defining difference between a fire and your half-eaten apple is speed: fire is an oxidation process that happens very fast, so that light, heat and sound are released — often with enough force and majesty to justify the ancients’ reverence.The sudden release of energy causes temperatures to rise, sometimes by thousands of degrees. And it also results in smoke, the toxic waste of fire’s leftovers.
The fire triangle and the fire tetrahedron
Fire TetrahedronThe fire triangle identifies the three needed components of fire:
fuel (something that will burn)
heat (enough to make the fuel burn)
and air (oxygen)
Explanation: i hope this helps sry its long
the valency of metal 'm' 1+. give the formula of its oxide
Answer:
[tex]M_{2}O[/tex]
Explanation:
Anything oxide is a compound with oxygen, and since oxygen is -2, it requires two of the metal's +1 to make it zero
In other words:
2(+1) + (-1) = 0
What do models of molecules and extended structures show?
Answer:
Examples of extended structures could include sodium chloride or diamonds. Examples of molecular-level models could include drawings, 3D ball and stick structures, or computer representations showing different molecules with different types of atoms. ... Examples of models could include drawing and diagrams
Explanation:
Find 6 examples of where chemistry and agriculture work together
Answer:
Chemistry deals with compounds, both organic and inorganic, and agriculture deals with the production of organic products using both organic and inorganic inputs Thus Chemistry forms an integral part of agriculture from molecular to organ level.
Explanation:
i hope this helps you! Have a nice day <33
Answerfcsdv fb fd
Explanation:
What does this diagram represent? (4 points) A glycerol molecule losing an H atom, and a fatty acid chain losing OH, forming H2O. 1. A saturated fat becoming unsaturated 2. A fat molecule forming through dehydration synthesis 3. The saturation of a triglyceride molecule 4. Dehydration synthesis breaking down a fat molecule
Answer:
This question is incomplete because of the absence of the diagram
Explanation:
The absence of the diagram makes the question incomplete, but it appears as if the content of the diagram has been described in the question (which is not totally clear).
The description provided in the question suggests the loss of a water during the formation of a triglyceride. This process described here is called dehydration synthesis. Dehydration synthesis is the process of joining two substances/compounds together leading to the loss of water molecule in the process.
From the explanation above, the correct option is 2. The fat molecule being formed is the triglyceride (through the process of dehydration synthesis).
can anyone do these problems?
Answer:
-76
296
228
603
485
Explanation:
Subtract 273 to 200 to get -76
add 273 to 23 to get 296
add 273 to -45 to get 228
subtract 273 to 876 to get 603
add 273 to 212 to get 485
What is a molecular orbital? Question 3 options: Another method of describing the orbitals of individual atoms A mixing of the atomic orbitals from an atom’s inner-most shell with those of the valence shell An area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside A mixing of the atomic orbitals from an atom’s valence shell
Answer:
An area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside
Explanation:
A molecular orbital is an area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside.
Molecular orbitals are formed by linear combination of atomic orbitals of about the same energy. The number of atomic orbitals that are combined to give molecular orbitals is the same as the number of molecular orbitals formed. The build up of electrons in molecular orbitals also follow the Aufbau principle, Hund's rule and Pauli exclusion principle.
An object with a negative acceleration could NEVER have a positive velocity. a. TRUE b. FALSE
Answer:false
Explanation:
What structures are present in a animal cell but not in a plant cell?
Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.
What keep forest fries burning so long?
Why do some forest fires get so large?
Why are the forest fires large some years and not other years.
Why are California forest fires getting worse?
Answer:
1. The warming climate has dried out California's landscape, turning it into a tinderbox. ... This is due in part to climate change: rising temperatures, have an exponential impact when it comes to setting the stage for catastrophic wildfires,
2. Due to the heat and temperature of the place and if the place is very dry.
3. It all depends on the weather. At times there can be less rain whereas at time there is a lot of rain or how much heat it is outside within years
4. Well California is really hot during the summer and it becomes really dry so that is the reason forest fires are getting worse
Round the following numbers to the number of significant figures indicated:
345 (2 s.f.) ___________
7850 (1 s.f.) ___________
24.68 (3 s.f) ___________
8.005 (3 s.f) ___________
0.005758 (3 s.f) ___________
1.25x1012 (2 s.f) ___________
Explanation:
Above we have simply looked the condition that where we put decimal point that gives your needed answer after round off.
For example:
we have to make 2 s.f from 345 so we kept decimal after 3 and we rounded off to make 3.5 from 3.45
Hope you got it
Your lab partner accidentally spills some acid on his wrist and watchband. You should: (Check all that apply.)
Answer: Remove the watch and watchband immediately, and rinse his wrist for at least 15 minutes to be sure all hazardous material has been washed away. Let the TA inspect his wrist to see if it is okay.
Explanation:
The question is incomplete, the choices are:
a. Take him to the safety shower, and make sure he stands under it for at least 15 minutes to be sure all hazardous material has been washed away. b. Remove the watch and watchband immediately, and rinse his wrist for at least 15 minutes to be sure all hazardous material has been washed away. c. Let the TA inspect his wrist to see if it is okay.
d. Rinse the watch band before allowing him to put it back on.
An acid is traditionally considered to be any chemical compound that, when dissolved in water, produces a solution with greater hydronium cation activity than pure water, i.e., a pH less than 7. Both corrosive acids (and also corrosive bases) are capable of destroying skin by catalyzing the hydrolysis of fats, which are chemically esters. Also, when acids attack metals, hydrogen gas is often released.
This is why your lab partner should remove the watch and watchband immediately, and rinse his wrist for at least 15 minutes to be sure all hazardous material has been washed away. This ensures that the acid is can not damage the skin. And also the person should make sure that someone qualified checks it to see if it is okay.
what tool would a scientist use to study fish eggs
Answer
1. Magnifier glass.
2. Ruler.
3. Scale.
Explanation:
1. To look and enspect the fish egg's.
2. To see how long and tall the fish egg's are.
3. To weight how heavey the fish egg's are.
Magnifier glass, scale, and ruler tools would a scientist use to study fish eggs
To look and inspect the fish egg's scientists will use the magnifier glass . To see how long and tall the fish's eggs are, scientists will use scale. To measure the weight of the fish eggs, scientists will use a ruler.
Hence, Magnifier glass, scale, and ruler tools would a scientist use to study fish eggs.
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A gas absorbs 10J of heat and is simultaneously
compressed by a const and external pressure
of 0.5 atm from 4L to 2L in volume What
is the change in the internal energy.
A. 101J b. 111J c.2J d. none of the above
Given :
Heat absorbs , Q = 10 J .
Pressure , [tex]P=0.5 \ atm =0.5\times 101325\ Pa[/tex]
Initial volume , [tex]V_i=4\ L[/tex] .
Final volume , [tex]V_f=2\ L[/tex] .
To Find :
The change in the internal energy .
Solution :
By first law of thermodynamics :
[tex]\Delta U=Q+W[/tex]
Here , W is work done , [tex]W=-P\Delta V=-P\times (V_f-V_i)[/tex]
Therefore,
[tex]\Delta U=Q-P(V_f-V_i)[/tex]
Putting values in SI units in above equation :
[tex]\Delta U=10 -(0.5\times 101325\times (2-4)\times 10^{-3})\\\\\Delta U=111\ J[/tex]
Therefore , option b. is correct .
Hence , this is the required solution .
Which of the following is not a step of the scientific method ?
A)Testing the hypothesis by experiments
B)making observations that lead to a question
C)forming a hypothesis to answer the question
D)changing the data to fit your hypothesis
Answer:
b
Explanation:
Note that : Hypothesis can be regarded as proposed explanation needed for a phenomenon.
The steps involves in scientific method are:
Making of observation about the topic that is needed to study. this is necessaryAsking of particular question ; once once background information has been gained about the topic then question needs to be asked and here hypothesis is formed by researcher, which gives relationship between variables.Testing of hypothesis and data collection, in this step the hunch is been put to test and use different method to collect needed data.Examination of result and drawing of conclusion. Once study has been designed by researcher and data has been collected it is time to examine those information and draw a conclusion.Learn more at: https://brainly.com/question/497944
Classify the following changes as physical or chemical changes. a. Water boils. b. Salt dissolves in water c. Milk turns sour d. A metal rusts.
Answer:
Water boils - physical change
Salt dissolves in water- chemical change
Milk turns sour- chemical change
metal rusts - chemical change
Explanation:
A chemical change refers to changes that are irreversible and the process involves the evolution of heat along with the formation of a new substance, examples include;Salt dissolves in water, Milk turns sour, metal rusts etc
The boiling of water is a physical change. The water can be cooled and the vapour condensed,hence, the boiling of water is a physical change.
Physical changes are easily reversible and no new substance is formed.
The least abundant gas in the air is
a. Xenon, Xe
b. Oxygen, O2
c. Water, H2O
d. Nitrogen, N2
Answer:
A.
Explanation:
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Xenon(Xe ) is the least abundant element on the earth. The correct option is option A.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Oxygen, water, and nitrogen are the most abundant molecule on the earth. Xenon is the least abundant amongst all given option. Xenon belongs to noble gas family. So, Xenon is not reactive at all. Xenon does not form any compound with any other element so its abundance on earth is very less.
Therefore, Xenon(Xe ) is the least abundant element on the earth. The correct option is option A.
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two difference between rhombic and monoclinic sulphur
Answer:
The key difference between rhombic and monoclinic sulphur is that the rhombic sulphur is the most stable allotropic form of sulphur that exists as rhombic octahedral crystals whereas the monoclinic sulphur exists as long, needle-shape prisms but, it is stable only at temperatures between 96◦C and 119◦C.
Explanation:
Thanks . I hope you got help
which part of potato plant stores food?
Answer:
Explanation:
The answer is rooot ok
the food is prepared in the form of starch in potato and ginger plants the food is stored in the Ender Ground Park gender and potato or underground stems while potato is a tuber Ginger is a rhizome in the food is stored in them in the form of starch so it is prepared in the leaves.
A true statement about mass is that
A. as the force of Earth's gravity on an object increases the object's mass increases.
B. mass is expressed in pounds
C. mass if often measured with a spring scale. D. mass is determined by comparing the mass of an object with a set of standard masses tha catalanse
Answer:
d
Explanation:
A: mass never increases or decreases. It is a value that is the same everywhere in the universe. A is not correct.
B: it can be but that is not the only unit that can be used
C: A spring scale measures force not mass.
D: The answer to this question is D if the word at the end is balance.
what are 2 examples of ethical research behaviour?
Answer:
Respect ConfidentialityExplanation:
*Hope this helps*