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.
An unlit match contains approximately 1,000 J of chemical energy When it burns, the match releases
thermal energy and light energy. After it has burned, the remaining match contains 250 J of chemical energy. If
the thermal energy was measured to be 400 J, how much light energy did the match emit?
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.
Which of the following equations best describes the energy at point
C, assuming energy is conserved?
O A. PEA= KEC
o B. PEA= KEc + PEC
C. PEg= KEC + PEC
O D. PEg = PEC
Answer:
The correct option is
B. PEA = KEC + PEC
Explanation:
The potential energy is the energy possessed due to position
From the image the point with the highest position and therefore the most potential energy and the lowest or zero kinetic energy is point A
Given that we have;
Total mechanical energy = The potential energy + The kinetic energy
Where there is constant total mechanical energy in the system, then, at the point A where the kinetic energy is zero, the potential energy is equal to the total mechanical of the system, we have;
Total mechanical energy = The potential energy at A = PEA
Total mechanical energy = PEA
At point C where we have the total mechanical energy presented as follows;
Total mechanical energy = Kinetic energy at C + Potential energy at C
Total mechanical energy = KEC + PEC
Therefore;
PEA = KEC + PEC.
You have a rock with a mass of 10 g in a density of 30. g/ml. What is the volume?
Answer provide in correct Significance Figure
Which of the following has a crystalline structure?
Answer:A copper-gold alloy has a crystalline structure
Explanation:
is saliva a element compound or mixture
Answer:
mixture
Explanation:
Answer:
mixture
Explanation:
10. How does a heterogeneous mixture differ from a homogeneous mixture? How are they similar?
why is a graduated cylinder most appropriate for measuring the volume of a liquid instead of a beaker ?
Answer:
Graduated cylinders are designed for accurate measurements of liquids with a much smaller error than beakers. They are thinner than a beaker, have many more graduation marks, and are designed to be within 0.5-1% error. ... Therefore, this more precise relative of the beaker is just as critical to almost every laboratory.
Explanation:
hope this helped!
When a strip of magnesium metal is touched to a flame, a bright light and a whitish substance are produced. Why is the burning of magnesium considered a chemical change? because the metal reaches a high temperature because the metal begins to melt because a new substance is formed because the metal is malleable
Answer:C
Explanation: on Edge
Answer: letter c is the answer
Explanation:
Describe the many different forms of energy involved with stretching and releasing a rubber band. What other processes are similar to this model?
Answer:
Conversion of kinetic energy to potential energy (chemo mechanical energy)
In the state of rest, the rubber is a tangled mass of long chained cross-linked polymer that due to their disorderliness are in a state of increased entropy. By pulling on the polymer, the applied kinetic energy stretches the polymer into straight chains, giving them order and reducing their entropy. The stretched rubber then has energy stored in the form of chemo mechanical energy which is a form of potential energy
Conversion of the stored potential energy in the stretched to kinetic energy
By remaining in a stretched condition, the rubber is in a state of high potential energy, when the force holding the rubber in place is removed, due to the laws of thermodynamics, the polymers in the rubber curls back to their state of "random" tangled mass releasing the stored potential energy in the process and doing work such as moving items placed in the rubber's path of motion such as an object that has weight, w then takes up the kinetic energy 1/2×m×v² which can can result in the flight of the object.
Explanation:
Answer:
Elastic potential energy------> kinetic energy --------> elastic potential energy
Explanation:
Elastic potential energy is the energy stored in a spiral spring. When a rubber band is stretched, this elastic potential energy is capable of doing work. This energy is just stored inside the rubber band and released when work is done by the rubber band.
Once the rubber band is released and it is in motion, the energy of the rubber is kinetic energy.
The system is similar to a simple pendulum.
.Put 8.4 x 10^-6 into standard notation.
Answer:
.0000084
Explanation:
Calculate the average atomic mass of boron (B), which has two isotopes: B-10 with 19.9% natural abundance, and B-11 with 80.1% abundance. Average atomic mass of boron = (f1)(M1) + (f2)(M2) Question 13 options: 12.1 amu 10.8 amu 9.2 amu 3.3 amu
Answer:
The average atomic mass of boron is found to be
10.80
Explanation:
also u answered it urself
Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Therefore, the average atomic mass of boron is 10.80amu. The correct option is option B.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.
Average atomic mass = (mass of first isotope× percent abundance of first isotope)+(mass of second isotope× percent abundance of second isotope)
Substituting the given values
Average atomic mass=( 10 amu × 19.9%)+(11 amu × 80.1%)
Average atomic mass=10.80amu
Therefore, the average atomic mass of boron is 10.80amu. The correct option is option B.
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Name the processes of making of salts???
Answer:
Table salt is made up of two elements
Sodium and Chlorine
Explanation:
[tex]Na + Cl_2 - > NaCl[/tex]
How Rock salt is gotten
: As the brine boils in the first effect, water evaporates producing further steam and causing salt crystals to grow. As the brine boils and the water starts to evaporate, a thick salt slurry of brine and salt crystals is formed.
Explanation:
[tex]\huge\underline\bold\blue{ƛƝƧƜЄƦ}[/tex]
crystalisationHope it helps
Why water is a compound but air is a mixture?
Answer:
Explanation-
Water is a compound because it is formed from hydrogen and oxygen, which is irreversible, having different properties but air is a combination of different gases in any proportion.
Claim: If I brush my teeth everyday, then I won't get cavities.
In this statement, the dependent variable is
I
Answer:
I wont get cavities it the dependent variable
Explanation:
Each of the following is a noncovalent interaction EXCEPT ________. a) Hydrogen bond b) Carbon-hydrogen bond c) Van der Waals d) Interaction Dipole-dipole
Answer:
CARBON-HYDROGEN BOND
Explanation:
The non-covalent interactions in the options are the hydrogen bond, the Van der Waal's bond, the dipole-dipole interaction. The odd one out of the options is the carbon - hydrogen bond.
The carbon-hydrogen bond is a covalent bond involving carbon and hydrogen atoms in which carbon shares its outer valence electrons with up to four hydrogen atoms either forming a complete shell with single bonds or complete shells with double or triple bonds. The type of bonding is found in hydrocarbons and other organic compounds. For example the alkanes, alkenes, alkynes and aromatic hydrocarbons.
The non- covalent bonds are the bonds that bind macro-molecules and do not involve the sharing of pairs of electrons. They are much more weaker than covalent bonds and are very important in the formation of proteins and nucleic acids. This type of bonding includes the electrostatic interactions, hydrogen bonds, hydrophobic bonds, Van der Waal's interactions. The different types of the non-covalent bonds differ in geometry, strength and specificity.
So therefore, carbon-hydrogen bond is the odd one of the non-covalent interactions listed in the options.
A(n) _________ is something that represents an idea or object to help people better understand it.
theory
method
model
observation
Answer: Model
Explanation: Did the quiz
How to solve for enthalpy for changes
The Gateway Arch in St. Louis, MO is approximately 630 ft tall. How many U.S. half dollars would be in a stack of the same height? Each half dollar is 2.15 mm thick.
Answer:
The number of half dollars in the stack of the height of the Gateway Arch in St. Louis is 89,313 half dollars
Explanation:
The given height of the Gateway Arch in St. Louis = 630 ft
The thickness of each half dollar = 2.15 mm
By conversion of factors, we have;
1 feet = 304.8 mm
Therefore;
630 ft. = 304.8 × 630 mm = 192,024 mm
The number of half dollars that will stack up to 630 ft or 192,024 mm, is therefore, given as follows;
The number, n, of half dollars in the stack of the height of the Gateway Arch in St. Louis = The height of the Gateway Arch in St. Louis/(The thickness of each half dollar)
n = 630 ft/(2.15 mm/(half dollar)) = 192,024 mm/(2.15 mm/(half dollar)) = 89,313.49 ≈ 89,313 half dollars
The number of half dollars in the stack of the height of the Gateway Arch in St. Louis = 89,313 half dollars.
5. Both kerosene and water are liquids at room temperature. Describe a procedure that can be used
to separate a mixture of the two liquids.
I found this. hope it helps!
What is callibration of temperature
ouch that hurts
What is Temperature Calibration? Temperature calibration refers to the calibration of any device used in a system that measures temperature. Most importantly, this usually means the temperature sensor, itself, which is typically a platinum resistance thermometer (PRT or PT-100), thermistor, or thermocouple.
identify and calculate the number of representative particles in 2.15 moles of gold.
Answer:
[tex]1.29 * 10^{24}[/tex] particles of gold
Explanation:
To convert the number of moles of any substance, in this case gold, you need Avogadro's number.
Avogadro's number is always [tex]6.022[/tex] × [tex]10^{23}[/tex]
[tex]2.15[/tex] moles Au × [tex]\frac{6.022*10^{23} particles}{1 mole Au}[/tex] = [tex]1.29 * 10^{24}[/tex] particles of gold
The number of representative particles in 2.15 moles of gold is 1.29 × 10 ²⁴.
What is mole ?The term mole is defined as the amount of substance containing 6.023 × 10²³ particles. 1 mol = 6.023 × 10²³ particles. This number is also called Avogadro's number. The symbol of mole is denoted by M.
A mole is a very important unit of measurement that chemists use. By using moles, chemists have to measure for very small things like atoms, molecules, or other particles.
The quantity amount of substance is a measure of how many elementary entities of a given substance are present in it.
To convert the number of moles of any substance, we required Avogadro's number.
Avogadro's number is always equal to 6.023 × 10 ²³
2.15 moles Au × 6.023 × 10 ²³ particles / 1 mole of Au
= 1.29 × 10 ²⁴ particles of gold
Thus, the number of representative particles in 2.15 moles of gold is 1.29 × 10 ²⁴.
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How are thermal energy and mass related?
Answer:
s
Explanation:
s
Answer:
Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter. ... Another factor also affects thermal energy. The other factor is mass
Explanation:
1. Form a hypothesis: As altitude increases, the air pressure decreases. How do you think the lower pressure will affect the following? (Circle your answers.) A. Freezing point: Increase, Stay the same or Decrease B. Melting point Increase Stay the same Decrease C. Boiling point: Increase Stay the same Decrease
Answer:
A. Freezing point: Increase.
B. Melting point: Decrease
C. Boiling point: Decrease
Explanation:
As we go up in higher altitudes the air becomes on and less dense, hence the decrease in the water vapor content at such altitude leads to a decrease of boiling point. Thus the air above is cool and much colder than at the ground surface. The vapor pressure is temperature-dependent and thus melting point will also decrease.Answer:
A increase
B decrease
C decrease
Explanation:
Question 7
(01.03 LC)
Which of the following happens to a molecule of an object when the object is cooled?
a) Its temperature increases,
b) It loses kinetic energy.
c) Its size increases.
d) It moves faster.
Answer:
D
Explanation:
Answer:
D
Explanation:
:)
I need to do this but i really don’t know what to write about so can everyone help me and just put something nice i should put
Answer:
Just say you expect all the help you need.
Explanation:
Say that you expect to get as much help as you can and that you expect to he welcomed and loved
An ecosystem describes a specific area where the organisms _____ _____ as a unit
Answer:
Live Together
Explanation:
Ten plants are grown in equal amounts of sunlight with equal amounts of water and varying amounts of fertilizer.
Fertilizer is a(n):
What are the parts of this water wheel system?Label the water wheel to show the matter and forms of energy that flow through the system?
Answer:
Water, wheel and paddles or bucket are the parts and mechanical energy is produced.
Explanation:
The parts of water wheel system are water, wheel and paddles or bucket. The main purpose of water wheel system is to generate useful energy by using the flowing or falling of water on the wheel. We use this water wheel system for the conversion of kinetic energy into mechanical energy such as water mill or hydroelectric plant in which the blades movement is responsible for the generation of electricity.
Which of the following equations can be used to solve volume of a solution using
molarity equation?
Answer:Molarity can be used to calculate the volume of solvent or the amount of solute. The relationship between two solutions with the same amount of moles of solute can be represented by the formula c1V1 = c2V2, where c is concentration and V is volume.
Explanation: c1V1 = c2V2
The equation that can be used to solve the volume of a solution using the molarity equation is:
Molarity (M) = moles of solute (mol) / volume of solution (L)
This equation can be rearranged to solve for the volume of solution:
Volume of solution (L) = moles of solute (mol) / Molarity (M)
By knowing the molarity of the solution and the number of moles of solute, you can substitute these values into the equation to calculate the volume of the solution.
It's important to note that this equation assumes the molarity is given in units of moles per liter (mol/L). If the molarity is given in a different unit, it may need to be converted before using the equation.
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Your question is incomplete, but most probably your full question was.
Which of the following equations can be used to solve volume of a solution using molarity equation?
Volume moles ÷ molarity
Volume-moles + molarity
Volume moles + molarity
Volume = moles x molarity
is evaporation of water a physical change or a chemical change ?
Answer:
Physical
Explanation:
Water is the chemical form of 2 hydrogen and 1 oxygen (H2O)
It is still H2O, as nothing made it chance that formula.