Answer:
350 J
Explanation:
The law of conservation of energy states that energy can neither be created nor destroyed but can only be converted from one form to another. This means that in a system, energy is not lost.
In this question, an unlit match contains approximately 1,000 J of chemical energy. When lit, thermal and light energy are emitted i.e. it gets converted to light and heat energy. If the thermal energy emitted was measured to be 400J, and the remaining match still contains 250J of chemical energy, then:
The amount of light energy emitted will be:
Total chemical energy (1000J) - {Remaining chemical energy (250J) + emitted thermal energy (400J)}
= 1000 - (400 + 250)
= 1000 - 650
= 350
Hence, the amount of light energy emitted is 350J
Note that, the amount of energy converted (thermal and light) and remaining chemical energy still equates the total chemical energy in the match.
Explain how you would test the presence of oxygen and hydrogen gases.
During radioactive decay, atomic nuclei of unstable isotopes
a.
give off nuclear radiation.
b.
are broken down by radioactive bacteria.
c.
form chemical bonds.
d.
are unchanged.
Use the table to answer the questions. What is the fastest time trial for the first quarter checkpoint? What is the slowest time trial for the first quarter checkpoint? What is the range of times measured for this checkpoint? All answers in seconds
Answer:
25
Explanation:
Answer:
Explanation:
What is the fastest time trial for the first quarter checkpoint?
2.02
seconds
What is the slowest time trial for the first quarter checkpoint?
2.15
seconds
What is the range of times measured for this checkpoint?
0.13
seconds
Four 5-gram blocks of metal are sitting out in the sun and absorb the same amount of heat energy. Use the following specific heat capacity data to determine which block will increase its temperature the most.
Substance Specific Heat Capacity (cal/g°C)
iron 0.11
copper 0.09
silver 0.06
lead 0.03
iron
copper
silver
lead
Answer:
lead
Explanation:
Which of the following is an example of using creativity while doing background research?
Organizing data in tables
Validating results by repetition
Drawing a conclusion
Writing a hypothesis
Answer:
B
Explanation:
Answer:
D. Writing a hypothesis
Explanation:
A science student wants to use distillation to separate a mixture of two
substances in the liquid state. For the student to be successful, which property
should be significantly different between the two liquids?
h-
ies
h-
Freezing point
Ability to dissolve a solid substance, such as table sugar
1
Ability to react with oxygen
O Boiling point
et
< Previous
Next
Answer:
Boiling point
Explanation:
Distillation is one of the most widely used separation technique in chemistry. It is used to separate a mixture of liquid substances with different boiling point. Hence, the basis of the separation is BOILING POINT DIFFERENCE.
In the procedure, the liquid substances are heated until they turn gaseous, which they do at different times considering their different boiling points. The separated components are then converted back to liquid states in a process called CONDENSATION.
Which of the following is a physical
change?
A iron rusting under water
B copper turning green in the air
C solid iodine subliming into a gas
D hydrogen and oxygen producing water
Answer:
C. solid iodine subliming into a gas
Explanation:
A physical change is a change that is reversible and can be reversed back into the original product. The atoms and molecules undergoes some rearrangement in the physical change. The process of change in the state of matters are placed under physical change. Solid iodine sublimes into purple gas on heating. The gas is then changed back to iodine crystals after being cooled. Hence, this is an example of a physical change.
Why was there no increase in the reaction rate with 8 g of substrate as compared to 4 g of substrate?
Answer:
Equilibrium over-saturated
Explanation:
In both were excessively-saturated in volume equilibrium and much more molecules would be required to see a growth in reaction rate.
So, we can say that there was no increase in reaction rate.
4 Al(s) + 3 O2(g) --> 2Al2O3 (s) What mole ratio would you use to convert from the given quantity of moles of aluminum to the wanted unit of moles of aluminum oxide?
Answer:
1:2
Explanation:
For every 4 moles of aluminum, there are 2 moles of aluminum oxide, so the mole ratio when converting from aluminum to alunmimum oxide is
2 moles aluminum oxide:4 moles aluminum. This can be simplified to 1:2.
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You are throwing a pizza party for 15 people and figure that each person will eat 4 slices. You call the pizza place and learn that each pizza will cost you $14.75 and it will be cut into 12 slices. How much is the pizza for this party going to cost you? Give the answer to the nearest cent.
Answer:
15 people x 4 slices so you’ll need 60 pieces
60/12(the amount of slices per pizza) =5
You need 5 pizzas. $14.78 x 5 = 73.90.
Explanation:
the answer is that one 73.90 is rounded nearest cent : ) took me a while to get it
Answer:
the cost of pizza for 15 people is $73.9
Explanation:
a pizza party for 15 and each person will eat 4 slices.
meaning the 15 people will eat 4 x 15 = 60 slices
Since each pizza will cost you $14.78 and will be cut into 12 slices.
`1 pizza = 12 slices = $ 14.78
60 slices = (14.78 x 60) / 12 = 886.8 /12 = $73.9the cost of pizza for 15 people is $73.9
The data were collected over five spring seasons. What is the difference between the number of frogs in the pond when the rainfall was 5 cm and when the rainfall was 20 cm?
Please help
Answer: they like deep water
Explanation: they do
What is a key difference between chemical and nuclear reactions?
A. In chemical reactions, new compounds are formed. In nuclear reactions, compounds are destroyed.
B. Chemical reactions involve electron rearrangements. Nuclear reactions involve changes to the nucleus.
C. Chemical reactions involve large changes in energy. Nuclear reactions absorb or release small amounts of energy.
D. In chemical reactions, only alpha radiation is emitted. In nuclear reactions, alpha, beta, and gamma decay may occur.
Answer:
B
Explanation:
Chemical reactions involve electron rearrangements. Nuclear reactions involve changes to the nucleus.
Answer:
B
Explanation:
On August 4, 2020, an explosion estimated at 1.2 kilotons of TNT (dynamite) destroyed
a port in Beirut, Lebanon. The sound from the explosion travelled at 767 mph (the speed
of sound). How long, in seconds, did it take for the sound to travel 50 km?
Answer:
it will take that explosin 15.34 millisecond
Explanation:
as the speed is 767 and distance is 50 so time will be 767/50=15.34milliseconds
What happens to the sound wave in echolocation?
Olt releases energy
O It is reflected
O It is refracted
O It is absorbed
Answer:
D
Explanation:
What is the noble gas notation For zinc
Answer:
The noble gas notation for zinc would be [Ar]3d^104s^2
Explanation:
I hope this helps you:) let me know if it does make sense, okay?
Round 2.6765 to two significant figures
Answer:
2.7 Significant Figures
Explanation:
The two significant figure value is "2.7".
Significant figures:Users were required to round up the given value, 2.6765, to two significant numbers in this challenge. Since the given number has no zeroes, all the digits are significant. Therefore, if we need and round the given number to 2 major digits, the number should only have two numbers.
Then we must select if the last digit to be preserved will be scaled up or down, and this will be determined either by digit following the last digit to be retained.Whereas if the digit after the last digit to be kept is greater than 5, the last digit should be rounded up.A digit following the last digit to be kept in the supplied number is 7, which is more than 5, hence using the aforementioned concept, So, the round figure value is "2.7".Therefore, the round figure value is "2.7".
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If 2a=3b and a=6 then b=
then b is 4
2a=3b since a=6
2x6=3b
12=3b
b=12/3
b=4
Answer:
b=4
Explanation:
2a=3b
2a=2*6
2*6=12
2a=12
12=3b
12/3=4
b=4
Which of these outcomes is conclusive evidence that mixing sugar in water is a physical change?
OA. There is no change in color.
OB. There is no precipitate formed.
OC. There is no gas given off.
OD. There is no molecular change,
Explanation:
Physical change can observe by physical appearance
OA = No change in color
other choices are chemistry change
Why would early Earth have been toxic for modern day animals? Why were cyanobacteria able to
survive
Answer: The surface of early earth was mostly molten and volcanic. The atmosphere was hot and highly toxic.
Explanation: Photosynthetic organisms were present when earth was primarily anoxic. photosynthetic organisms were present when earth was primarily anoxic. the early forms of photosynthesis did not produce oxygen as a waste product. cyanobacteria carry out anoxic photosynthesis. the early forms of photosynthesis did produce oxygen, but it was not enough to make a difference in the atmosphere. the early forms of photosynthesis were carried out in the water, and there was no way for the oxygen to move into the atmosphere.
1
Early earth have been toxic for modern day animals as at that time atmosphere is oxygen free, and cyanobacteris is able to survive due to symbiosis.
What are cyanobacterias?
Cyanobacteria is a group of microorganisms that are related to bacteria but can perform photosynthesis. They are prokaryotic and are thought to be the earliest form of life on the planet.
Early earth atmosphere may proof toxic for modern day animals because at the earliest time, atmosphere is oxygen free means no oxygen is present in the atmosphere. And in the today scenario we can't imagine life without oxygen.
Cyanobacteria were able to suvive in that early atmosphere through alternative option like symbiosis in which a cell merges with another cell in order to the survival of both cells.
Hence life is toxic at the early time because of the absence of oxygen.
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what is astrobiology
Answer:Astrobiology, formerly known as exobiology, is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe.
Explanation:
Answer: the branch of biology concerned with the study of life on earth and in space.
Explanation: Astrobiology is an interdisciplinary scientific field concerned with the origins, early evolution, distribution, and future of life in the universe. Astrobiology considers the question of whether extraterrestrial life exists, and if it does, how humans can detect it.
is the study of matter and energy ,and the interactions between the two through forces and motion
The study of matter and energy ,and the interactions between the two is through forces and motion which is a part of physics.
What is motion?Motion is defined as a phenomenon which is described with respect to change in object's position with respect to time.It is given in terms of displacement,velocity,distance ,acceleration,speed.
Branch of physics which deals with motion of objects without any reference to it's cause is called kinematics while the branch which studies forces and their effects on motion is called as dynamics.
Motion applies to various systems like objects,bodies, matter particles ,radiation ,curvature.There are three laws of motion which are proposed by Newton.Classical mechanics is based on Newton's law of motion.Relativistic mechanics is based on modern kinematics.
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Where did the mass of the forest trees come from? What happens to that mass when the forest burns?
Answer:
when the forest burns all the trees die and the ground becomes more fertile.
The mass of forest trees is due primarily due to the presence of carbon in them. When the forest burns the mass is not destroyed as burning does not cause changes in matter.
What is the law of conservation of mass?
Law of conservation of mass is a law which states that during a chemical reaction mass is neither created nor destroyed.Rather it is the only form of the matter which changes.
In chemistry, the law of conservation of mass can be stated as during a chemical reaction the mass of products is always equal to the mass of the reactants.
This law is important in chemistry as it helped scientists to understand that during a chemical reaction substances do not disappear rather they are transformed to new substances of equal mass.
Law of conservation of mass was given in the year 1774 by French chemist Antoine Lavoisier and hence is also known as Lavoisier's law.
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Thomson's model suggested that electrons were mixed into the sphere of an atom much like raisins ?
What is the mass, in grams, of a 12.0cm³ sample of aluminum? The density of aluminum is 2.70g/cm³
Answer:
The answer is
32.4 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume of aluminum = 12 cm³
Density = 2.70 g/cm³
The mass of aluminum is
mass = 2.7 × 12
We have the final answer as
32.4 gHope this helps you
Which statement about melting and boiling points is true? Question 3 options:
A. As you move down group 7A in the periodic table, the melting and boiling points of the elements decrease.
B. As you move up group 8A in the periodic table, the melting and boiling points of the elements increase
. C. Smaller atoms in group 8A require higher boiling points for the molecules to separate from each other than larger atoms in group 8A.
D. Larger atoms in group 8A require higher boiling points for the molecules to separate from each other than smaller atoms in group 8A.
Answer:
B
Explanation:
I believe it is B but I am not entirely sure! don't do this is B doesn't sound or look right to you!
Answer:
Its D
Explanation:
Larger atoms in group 8A require higher boiling points for the molecules to separate from each other than smaller atoms in group 8A.
What does the term division of labor mean as it relates to cells?
Answer:
what each cells job is divided
Explanation:
Sprinkler powder on the carron board _________ friction
Answer:
Sprinkler powder on the carron board reduce friction.
how is matter and energy conserved when liquid is frozen
Answer:
The big energy change when water freezes is in the potential energy of interactions between the water molecules.
Explanation:
I am not to sure if this is correct, but I hope it helps in some way.
Extensive properties _______________ useful for identifying a substance because the substance may be present in any _______________. Some _______________ properties, such as _______________, aren't useful either.
Answer: Extensive properties such as the mass, volume and entropy of systems are additive for subsystems, useful for identifying a substance because the substance may be present in any physical properties. Some intensive properties, such as temperature, refractive index and density, aren't useful either.
Explanation: According to scientific studies, Physical properties of materials and systems can often be classified as being either intensive or extensive, according to how the property changes when the size (or extent) of the system changes. Based on IUPAC classification, an intensive quantity is one whose magnitude is independent of the size of the system whereas an extensive quantity is one whose magnitude is additive for subsystems. This explains the corresponding mathematical ideas of mean and measure, respectively.
- At sea level, water boils at 100°C. This is an example of an)
a chemical property.
c. physical property.
b. extensive property.
d. chemical change.
Answer:
d
Explanation:
The measurement of boiling point is a physical property it involves only physical changes and not any chemical change. Hence, option c is correct.
What is physical properties?Physical properties of a substance include properties such as boiling point, melting point, density, mass, solubility etc. These are all characterised with a change in physical state of the substance and not any chemical reactions.
Boiling point of a substance is the temperature at which the substance converts from its liquid state to vapor state where the vapor pressure of the gas phase above the liquid is equal to the atmospheric pressure.
Boiling of a substance does not involve any making or breaking of chemical bonds and not producing a new compound. Therefore, boiling point is a physical property.
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