Fogging a mirror with your breath is a physical change because it involves a phase change of water vapor condensing and adsorbing to the mirror surface. Phase changes are physical changes.
Breaking a bone is a physical change insofar as we're focusing on the "breaking" part.
Mending a broken bone, however, is a different story. Bones are living things: They consist of tissues that in turn consist of cells. The actual mending process involves some very complicated biochemistry. Suffice it to say that mending a broken bone would be a chemical change.
Burning paper is a chemical change. Burning anything implies combustion, which is a chemical reaction where some fuel is oxidized (usually by oxygen gas, producing carbon dioxide gas and water vapor).
Slicing potatoes for fries is a physical change. You can slice, dice, smash, mash, stretch, bend, compress, or grind a potato: What you will have is still a potato (okay, there are some chemical changes going on as you're rupturing cells in the process, causing them to release their contents which may participate in chemical reactions). But the key, again, is that cutting up some material doesn't fundamentally change the chemical identity of that material.
Mixing sugar with coffee actually involves two physical processes: the mixing and the (presumed) solvation of the solid sugar particles as they dissolve into the coffee. In either case, either mixing or dissolving would be a physical change. The sugar molecules are still in the coffee and are chemically unchanged.
Frying chicken is a chemical change. In fact, frying chicken likely entails several different types of chemical changes. The common thread among them is that frying involves breaking chemical bonds in and on the chicken by the addition of thermal energy, and new chemical bonds end up being formed. That's the hallmark of a chemical change.
A nail rusting is a chemical change. Rusting is an electrochemical process; the familiar corrosion of iron into rust is, at bottom, a chemical reaction where iron reacts with oxygen to form iron oxides (often catalyzed by the presence of water and salts).
A paper ripping is analogous to slicing potatoes: it's a physical change. If you ripped one sheet of paper into two halves, each half would retain all the chemical properties of the original sheet.
Likewise, wood burning is analogous to burning paper, and as such is a chemical change. Again, combustion is a chemical process.
As we said earlier with sugar in coffee, mixing in itself is a physical process. While it may seem like you've permanently changed the nature of the water by dyeing it with food coloring, the molecules comprising the food coloring are simply dispersed within the vast sea of water molecules. There are no intramolecular bonds that are broken or formed; the chemical identities of all the substances here are preserved. So, this is a physical change.
Food molding (rotting) is a chemical change. Rotting is biochemical decomposition: the chemical bonds that make up the food are broken down by enzymes released by the mold.
Writing on paper, whether it be with a pen, pencil, crayon, or marker, is a physical change. The molecules from the writing instrument are physically stuck to the paper. But unless you're writing on paper by, say, burning letters onto it, there are no chemical changes occurring when the writing instrument meets the paper.
As with writing on paper, dyeing fabric can be a physical change. The dye consists of molecules that interact with light in a way that we perceive a certain color. When dyeing fabric, these molecules are transferred and fixed into the fabric by adsorption, absorption, and other intermolecular phenomena. But the molecules of the dye (and the molecules in the fabric) don't experience any breaking and forming of bonds. All of the substances involved retain their chemical identities.
However, it's possible that, depending on the dye, there may be chemical changes involved. Some dyes, appropriate named "reactive dyes," undergo chemical reactions with their substrate (which, in this case, would be the fabric), or dyes may be used that undergo chemical reactions with one another, both of which would constitute chemical changes. And it can depend on what you mean by "dyeing": Bleaching a colored shirt can technically be conceived of as "dyeing" the shirt white, and this process involves cleavage of bonds within the color-producing molecules in the fabric by reacting with the molecules in the bleach.
So, for dyeing fabric, it can be a physical or chemical change depending on the dye.
How many atoms are in a single molecule of FeCl2
formula of barium hydroxide and potassium superoxide
Answer:
Barium hydroxide Ba(OH)2
Potassium superoxide KO2
Which of these is NOT found in the earths crust?
Oxygen
Iron
Sulphur
Helium
Explanation:
helium
Helium gas is not found in earth crust
The empirical formulae of a compound is CH2O. The relative formula mass for the molecular formula is 180. What is the molecular formula?
Answer:
ch20 is the empirical formula for glucose , c6h1206 is the molecular formula .
Describe the effects of anaerobic respiration on the body and explain the effects on the body
Answer:
In anaerobic respiration, glucose breaks down without oxygen. The chemical reaction transfers energy from glucose to the cell. Anaerobic respiration produces lactic acid, rather than carbon dioxide and water. Unfortunately this can lead to painful muscle cramps.
please mark my anSwEr as brainlist
Answer:
In anaerobic respiration, glucose breaks down without oxygen. The chemical reaction transfers energy from glucose to the cell. Anaerobic respiration produces lactic acid, rather than carbon dioxide and water. Unfortunately this can lead to painful muscle cramps.
Explanation: Living things need energy for everything they do, including growing and reproducing. This energy comes from glucose. All animals and humans get glucose through eating it, but plants need to make their own glucose during photosynthesis.
Plants and animals transport glucose and oxygen to tiny structures in their cells, called mitochondria. Here, the glucose and oxygen take part in a chemical reaction. The reaction is called aerobic respiration, and it produces energy which transfers to the cells.
Aerobic respiration makes two waste products:carbon dioxide and water. Animals remove carbon dioxide from their bodies when they breathe out. In daytime, plants use some of this carbon dioxide for photosynthesis. At night, they release the carbon dioxide to their surroundings.
what is the conclusion that males are stronger than females
True/False. A program is an algorithm that has been coded into something that can be run by a machine. *
Answer:
true
Explanation:
when combined the two substances together in the cup, the product can be described as a ____ or ____ (there are two possible answers . you just need to choose one )
1. white gas
2. white liquid
3. white solid
Select the correct answer.
Copper carbonate (CuCO3) reacts with hydrochloric acid (HCl) according to this equation:
CuCO3(s) + 2HCl(aq) → CuCl2(aq) + H2O(l) + CO2(g).
Which statement correctly describes the substances in this reaction?
A.
Exactly one product and two reactants are either liquid or dissolved in water.
B.
Exactly one of the reactants is in a water-based solution, but none of the products are.
C.
The reactants include both a liquid and a gas.
D.
Exactly one reactant is a solid, and exactly one product is a gas.
E.
The products include a solid, a liquid, and a gas.
Answer:
I think the answer would be option d.
hope it helps.
What are the two types of microscopes?
+
Answer:
1) The light microscope. The common light microscope used in the laboratory is called a compound microscope because it contains two types of lenses that function to magnify an object. The lens closest to the eye is called the ocular, while the lens closest to the object is called the objective. Most microscopes have on their base an apparatus called a condenser, which condenses light rays to a strong beam.
2) Other light microscopes. In addition to the familiar compound microscope, microbiologists use other types of microscopes for specific purposes. These microscopes permit viewing of objects not otherwise seen with the light microscope.
3) The fluorescent microscope uses ultraviolet light as its light source. When ultraviolet light hits an object, it excites the electrons of the object, and they give off light in various shades of color. Since ultraviolet light is used, the resolution of the object increases. A laboratory technique called the fluorescent‐antibody technique employs fluorescent dyes and antibodies to help identify unknown bacteria.
If the electromagnet in the PhET simulation is disconnected from the battery, the compass needle will...
Answer: Point north.
What is the key difference between a liquid and a gas?
A. average kinetic energy
B. intermolecular attractions
C. the ability to flow
B. intermolecular attractions.
why is carbon classified as an element
Answer:
D: It combines with oxygen to form a gas.
Explanation:
Carbon is classified as an element because of its ability to combine with other elements and form a new substance or compound.
Looking at the options, the correct option in the light is option D
How many times as bright as a light that is 90 m away from you does a light that is 10 m away from you appear?
Answer:
81 x as bright
Explanation:
The intensity of light is dependent on distance according to this simple equation:
(90/10)^2 = 9^2
= 81
This was derived from the inverse-square law. Respectively a light that is 10 m away from you is 81 x as bright.
The surface currents of Earth’s oceans are most likely created by which of the following?
Answer:
global wind patterns. the rotation of the Earth. the shape of the ocean basins.
Explanation:
PLESE HELP! Which of the following sugar solutions is the most concentrated?
Select one:
a. 25 g of sugar in 60 mL of water
b. 2 g of sugar in 100 mL of water
c. 15 g of sugar in 25 mL of water
d. 12 g of sugar in 30 mL of water
c.15gof in25mlof wather
The sugar solution that is the most concentrated is 15 g of sugar in 25 mL of water.
CONCENTRATION:
The concentration of a solution is related to the amount of a substance and its volume. The concentration of a solution is directly proportional to the amount of a substance but inversely proportional to the volume. This means that the concentration increases with an increasing amount of substance but decreases with an increasing volume. According to this question, 15g of sugar is the highest amount and it dissolves in 25mL of water, which is the lowest volume. Therefore, it is the most concentrated sugar solution.Learn more at: https://brainly.com/question/202460?referrer=searchResults
A car is driving directly south down a road. It slows down to
stops at a few stop signs, and then, accelerates up to 30 miles
per hour.
Is the car's velocity changing? Why or why not?
A 40 g gold coin is heated from 10°C to 50°C (CAuis 0.13 J/g−°C). What is the △H?
The answer would be +208 J.
5. What is the charge on a single proton?
Answer:
it may be +1 or -1 hope this help
An atom is a kind of stuff that cannot be further decomposed chemically. Therefore, the charge on a single proton is +1.
What is atom?
The building block of an element is an atom. An atom is a kind of stuff that cannot be further decomposed chemically. The three main components of an atom are protons, neutrons, plus electrons.
Some substances are either bigger or smaller than atoms. Instances of chemical species that aren't commonly regarded as atoms include protons, neutrons, and electrons, which are atom-related particles. Atoms make up molecules and compounds, however they are not actual atoms. Salt is an example of a molecule and a compound (NaCl). The charge on a single proton is +1.
Therefore, the charge on a single proton is +1.
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How many valence electrons are in an atom of Zinc (III)
Atomic number 30
Atomic mass 65.38
a 12
b 35
c 3
d 30
Answer:
A.) 12
Explanation:
The number of valence electrons= the group number
Answer:
c) 3 valence elcertons
Level 3
Q1
Forces that are equal but opposite
are called
A. Net force
B. Friction
C. Centripetal force
D. Balanced forces
option D Balanced force
What is the volume of a container containing 7.59 moles of krypton gas at STP?
170.034 L is the volume of a container containing 7.59 moles of krypton gas at STP.
What is an ideal gas equation?
The ideal gas equation, pV = nRT, is an equation used to calculate either the pressure, volume, temperature or number of moles of a gas.
Using the ideal gas equation
PV =nRT
Where P is the pressure
V is the volume
n is the number of moles
R is the ideal gas constant (R = 0.08206 L atm mol⁻¹ K⁻¹)
T is the temperature.
From the given information
V =?
n = 7.59
and at STP
P = 1 atm
T = 273 K
Putting the parameters into the formula, we get
PV =nRT
1 atm x V = 7.59 mol x 0.08206 L atm mol⁻¹ K⁻¹ x 273 K
V = 170.034 L
Hence, 170.034 L is the volume of a container containing 7.59 moles of krypton gas at STP.
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Why can't hydrogen be grouped in a family?
Answer:
A Family Portrait
That element is NOT in the family. When we told you about families, we said that they were groups of elements that react in similar ways. Hydrogen is a very special element of the periodic table and doesn't belong to any family. While hydrogen sits in Group I, it is NOT an alkali metal.
Answer:
Explanation:
The chemical properties are so different and cannot be group into a family Hydrogen is the simplest, smallest and lightest of the elements. Unlike the other elements of the periodic table, the combination of properties it exhibits doesn't match any one single grouping or family.
What is the formula for sulfate?
What is the charge of sulfate?
What is the correct formula for copper (II) sulfate?
Answer:
SO₄²-, -2, CuSO4
Explanation:
Dang that was long.
state the kinetic theory of matter
Answer:
The kinetic theory of matter (particle theory) says that all matter consists of many, very small particles which are constantly moving or in a continual state of motion.
What type of chemical reaction is given by the following balanced equation:
Al₂O3 → AL+ O₂
Answer:
Decomposition
Explanation:
A student uses 0.0821 L• atm/mol • K as the value of the gas constant. What is most likely true about the variables in the ideal gas law?
P has the units of liters • atmospheres, and T has the units of kelvin.
P has the units of liters • atmospheres, and T has the units of degrees Celsius.
V has the units of liters, and T has the units of kelvin.
V has the units of liters, and T has the units of degrees Celsius.
Answer: V has the units of liters, and T has the units of kelvin.
Ideal gas law: p·V = n·R·T.
atm · L = mol · L·atm/mol·K · K; both side of equatation have same values.
R = 0,08206 L·atm/mol·K; universal gas constant.
p is pressure of the gas, unit is standard atmosphere (atm).
V is volume of the gas, unit is liters (L).
n is amount of substance of the gas; unit is mole (mol).
T is temperature of the gas, unit is Kelvin (K
Hope this helps!!
Explanation:
Answer: V has the units of liters, and T has the units of kelvin.
Explanation:
How many moles are in 435 grams of sulfur, S?
Answer:
32.065 is the correct answer.
magine that you need to take a medicine that the doctor has prescribed for you. Explain why scientists who developed that medicine would need to know whether or not the compound in that medicine is polar. How might a polar medicine behave differently as it dissolved in the body than a nonpolar medicine would?
Answer:
hi
Explanation:
The compound in medicines should be non polar. Therefore scientists need to be sure of using compounds that are non polar in nature so they pass through the cell membrane and enter into the blood circulation of the body and perform its due function.
35. 124.31 g of silver nitrate reacts with 52.89 g of sodium chloride.
g
a. What is the mass of the products?
Answer: Thus mass of products is 177.2 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical reaction is:
[tex]AgNO_3+NaCl\rightarrow NaNO_3+AgCl[/tex]
mass of silver nitrate [tex](AgNO_3)[/tex] = 124.31 g
mass of sodium chloride [tex](NaCl)[/tex] = 52.89 g
mass of reactants = mass of silver nitrate [tex](AgNO_3)[/tex] +
mass of sodium chloride [tex](NaCl)[/tex] = 124.31 g + 52.89 g = 177.2 g
Thus mass of products = mass of reactants = 177.2 g