Grinding of glass sanding of wood are physical changes. Rusting of iron and burning candle are chemical changes.
What are chemical changes ?Chemical changes involves the formation or breaking of chemical bonds that leads to a new product. Whereas, physical changes does not involves any change in chemical bonds. Phase change, change in size, shape etc. are physical changes.
Grinding glass will does not make any change in chemical bonds of glass materials . Just their size gets reduces and forms their dust particles. Thus, it is a physical change. Sanding the wood also a physical change.
Rusting of iron is the formation of red iron oxide by the reaction of iron with oxygen from air or water. This oxide will spread over the surface of the metal and eventually gets corroded. This is a chemical change where a new product is formed.
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Which element has a lower ionization energy: F or I?
Answer:
I just did this question and it’s I
Explanation:
Answer:
Iodine (I) has a lower Ionization Energy.
Explanation:
Our Periodic Trend for Ionization Energy is up and to the right.
We know that Fluorine and Iodine are both in Group 17. However, Fluorine is in Period 2 and Iodine is in Period 5.
According the Coulomb's Law, the greater the distance between the electrons and the nucleus, the less Forces of Attraction (FOA) there are. Since Iodine has a lot more electrons than Fluorine, and those electrons are spread out farther from the nucleus, they will have less FOA acting on them. Therefore, it will require less energy to remove those electrons from Iodine.
Since Iodine has so many electrons, it will also have more core electrons than Fluorine. This will create the Shielding Effect, where the core electrons "shield" the nucleus' FOA. With the reduced FOA, the outer electrons aren't held as closely to the nucleus as the core electrons. Since higher sublevels also means more energy, those outer electrons contain a lot of energy. All electrons want to have the lowest energy level possible, and since the FOA is reduced, less energy is needed to remove the electrons of Iodine rather than Fluorine.
How many hydrogen atoms are there in 1.15 g of methane (CH4)?
The volume of a gas is 590 mL at 384 kPa pressure. What will the volume be when the pressure is changed to 546 kPa, assuming the temperature
remains constant?
Answer:
The answer is 414.95 mLExplanation:
To find the volume when the pressure is changed to 546 kPa , we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the final volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{384000 \times 590}{546000} = \frac{226560000}{546000} \\ = 414.945054...[/tex]
We have the final answer as
414.95 mLHope this helps you
B. For items 6-10, identify at least one element present in each of the following
food products:
8.
7.
6.
9.
10.
A student is trying to calculate the density of a ball. She already knows the mass, but she needs to determine the volume as well. Which of the following formulas can be used to calculate the volume of the ball?
Group of answer choices
V equals four-thirds times pi times r cubed
V equals one-third times pi times r squared times h
V = s3
V = πr2h
Answer:
V equals four-thirds times pi times r cubed
Explanation:
Volume = a³ , where a is length of each side. Volume = l × w × h , where l is length, w is width and h is height. Volume = 4/3 πr³ , where r is the radius. Volume = πr²h , where r is the radius and h is the height.
The distance north or south of the equator is called
O equator
O latitude
O longitude
O pole
Answer:
Latitude
I hope this helps!
A silver chafing dish has a specinc heat capacity of a mass of 1350 How much heat transferred to increase the temperature of by 15.0 degrees * C (For the purpose of of transfer, the dish as the system )
Answer:
I'm not really sure how to answer it but this is the best I can do:
If the capacity of a mass is 1350 and heat is transferred to increase the temperature by 15. degrees Celcius then the amount of heat that needs to be transferred would be about 45 degrees.
Explanation:
I'm sorry if it's wrong or not exactly the way it's supposed to be answered, I'm not very good with math and temperature problems. But i hope it helps! :)
Select the keyword or phrase that will best complete each sentence.
1. _____anions are strong nucleophiles that open epoxide rings by an SN2 mechanism.
2. _____tautomers have an O-H group bonded to a C=C.
3. _____are formed from terminal alkynes with the addition of water using BH3 then H2O2.
4. _____are constitutional isomers that differ in the location of a double bond and a hydrogen and exist in an equilibrium with each other.
5. _____are compounds that contain a carbon-carbon triple bond.
6. _____of a terminal alkyne adds BH? to the less substituted, terminal carbon.
7. _____have a C=O and an additional C-H bond.
8. _____are formed from terminal alkynes with the addition of water using H2SO4 and HgSO4.
Answer:
1) acetylide
2) enol
3) aldehydes
4) tautomers
5) alkynes
6) Hydroboration
7) Keto
8) methyl ketones
Explanation:
Acetylide anions (R-C≡C^-) is a strong nucleophile. Being a strong nucleophile, we can use it to open up an epoxide ring by SN2 mechanism. The attack of the acetylide ion occurs from the backside of the epoxide ring. It must attack at the less substituted side of the epoxide.
Oxomercuration of alkynes and hydroboration of alkynes are similar reactions in that they both yield carbonyl compounds that often exhibit keto-enol tautomerism.
The equilibrium position may lie towards the Keto form of the compound. Usually, if terminal alkynes are used, the product of the reaction is a methyl ketone.
Consider the reaction: CH3COOH(aq)+H2O(l)⇌H3O+(aq)+CH3COO−(aq) K=1.8×10−5 at 25∘C Part A If a solution initially contains 0.265 molL−1 CH3COOH, what is the equilibrium concentration of H3O+ at 25∘C?
Answer:
[tex][H_3O]^+=2.18x10^{-3}M[/tex]
Explanation:
Hello.
In this case, for the given ionization chemical reaction of acetic, the equilibrium expression is:
[tex]Ka=\frac{[H_3O^+][CH_3COO^-]}{[CH_3COOH]}[/tex]
Since aqueous species are considered only. Next, by introducing the reaction extent [tex]x[/tex] based on the ICE table, in which it equals the concentration of both H3O+ and CH3COO-, we can also write:
[tex]1.8x10^{-5}=\frac{x*x}{0.265M-x}[/tex]
As the acid ionization constant is small in comparison to 0.265 M, we can make an approximation to compute [tex]x[/tex] as shown below:
[tex]1.8x10^{-5}=\frac{x*x}{0.265M}\\\\x=\sqrt{1.8x10^{-5}*0.265}= 2.18x10^{-3}M[/tex]
It means that the concentration of H3O+ is:
[tex][H_3O]^+=2.18x10^{-3}M[/tex]
Best regards.
A solution of acetic acid (Ka = 1.8 × 10⁻⁵) with an initial concentration of CH₃COOH of 0.265 mol/L has an equilibrium concentration of H₃O⁺ at 25 °C of 2.18 × 10⁻³ M.
Let's consider the reaction for the acid ionization of acetic acid.
CH₃COOH(aq) + H₂O(l) ⇌ H₃O⁺(aq) + CH₃COO⁻(aq)
The acid ionization constant (Ka) is 1.8 × 10⁻⁵ and the initial concentration of the acid (Ca) is 0.265 mol/L.
Considering that it is a weak monoprotic acid, we can calculate the equilibrium concentration of H₃O⁺ at 25 °C using the following expression.
[tex][H_3O^{+} ]= \sqrt{Ka\times Ca } = \sqrt{1.8\times 10^{-5} \times 0.265 } = 2.18 \times 10^{-3} M[/tex]
A solution of acetic acid (Ka = 1.8 × 10⁻⁵) with an initial concentration of CH₃COOH of 0.265 mol/L has an equilibrium concentration of H₃O⁺ at 25 °C of 2.18 × 10⁻³ M.
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Carbon-14 is likely to undergo which of the following nuclear decay process, in order to:
a)beta decay; to reduce the number of neutrons
b)alpha decay; to increase the number of protons
c)positron emission; to reduce the number of neutrons
d)electron capture; to increase the number of protons
Answer:
a)beta decay; to reduce the number of neutrons
Explanation:
When an isotope decays by beta decay, a neutron is converted into a proton, an electron and a neutrino (a particle that serves to balance spins). This process reduces the neutron/proton ratio.
During the beta decay of carbon-14, an atom of 14C decays into an atom of 14N. Hence the number of protons in the atom increases by one, creating a nitrogen atom.
The alkaline earth metals are
Answer:
Calcium, Magnesium, Barium, strontium, Beryllium, Radium
Explanation:
sorry if im wrong.....:(
You are given a bottle of impure CoSO4 7H2O which is thought to be 74.4% by weight CoSO4 7H2O. You propose to run your own analysis to find out. What weight of sample should you take to get 0.345 g of BaSO4?
Answer:
[tex]m_{CoSO_4\ \ 7H_2O}^{sample}=0.558gm_{CoSO_4\ \ 7H_2O}[/tex]
Explanation:
Hello.
In this case, considering a representative reaction by which BaSO4 is yielded via CoSO4, for instance:
[tex]CoSO_4\ \ 7H_2O+BaCl_2\rightarrow BaSO_4+CoCl_2+7H_2O[/tex]
Since it is desired to obtain 0.345 g of BaSO4 (molar mass = 233.38 g/mol), we can compute the theoretical mass of CoSO4·7H20 (molar mass = 281 g/mol) via the following stoichiometric procedure:
[tex]m_{CoSO_4\ \ 7H_2O}=0.345gBaSO_4*\frac{1molBaSO_4}{233.38 gBaSO_4}*\frac{1molCoSO_4\ \ 7H_2O}{1molBaSO_4} *\frac{281.00gCoSO_4\ \ 7H_2O}{1molCoSO_4\ \ 7H_2O} \\\\m_{CoSO_4\ \ 7H_2O}=0.415gCoSO_4\ \ 7H_2O[/tex]
Next, given the percent purity of the cobalt (II) sulfate heptahydrate, we can compute the mass of the whole sample as shown below:
[tex]m_{CoSO_4\ \ 7H_2O}^{sample}=0.415gCoSO_4\ \ 7H_2O^{pure}*\frac{100gCoSO_4\ \ 7H_2O^{sample}}{74.4gCoSO_4\ \ 7H_2O^{pure}} \\\\m_{CoSO_4\ \ 7H_2O}^{sample}=0.558gm_{CoSO_4\ \ 7H_2O}[/tex]
Best regards!
To obtain 0.345 g of BaSO₄, we need to weigh 0.559 g of CoSO₄.7H₂O with a purity of 74.4%.
Let's consider a possible reaction for the obtaining of BaSO₄ from CoSO₄.7H₂O.
CoSO₄.7H₂O(aq) + Ba(NO₃)₂(aq) ⇒ BaSO₄(s) + Co(NO₃)₂(aq) + 7 H₂O(l)
We want to find the mass of CoSO₄.7H₂O required to form 0.345 g of BaSO₄. We will consider the following relationships:
The molar mass of BaSO₄ is 233.38 g/mol.The molar ratio of BaSO₄ to CoSO₄.7H₂O is 1:1.The molar mass of 281.10 g/mol.[tex]0.345gBaSO_4 \times \frac{1molBaSO_4}{233.38gBaSO_4} \times \frac{1molCoSO_4.7H_2O}{1molBaSO_4} \times \frac{281.10gCoSO_4.7H_2O}{1molCoSO_4.7H_2O} =0.416gCoSO_4.7H_2O[/tex]
The purity of the sample is supposed to be 74.4%, that is, there are 74.4 g of CoSO₄.7H₂O every 100 g of sample. The mass of the sample that contains 0.416 g of CoSO₄.7H₂O is:
[tex]0.416gPure \times \frac{100gSample}{74.4gPure} = 0.559gSample[/tex]
To obtain 0.345 g of BaSO₄, we need to weigh 0.559 g of CoSO₄.7H₂O with a purity of 74.4%.
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What is the number of moles in .025g (NH4)2Cr2O7?
Answer:
252.06492
Explanation:
How many grams (NH4)2Cr2O7 in 1 mol? The answer is 252.06492.
We assume you are converting between grams (NH4)2Cr2O7 and mole.
You can view more details on each measurement unit:
molecular weight of (NH4)2Cr2O7 or mol
The SI base unit for amount of substance is the mole.
1 grams (NH4)2Cr2O7 is equal to 0.0039672319337415 mole.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between grams (NH4)2Cr2O7 and mole.
Type in your own numbers in the form to convert the units!
Provide the name of the compound composed of two nitrogen atoms and four oxygen atoms,
Outer core made of alloy metal, mostly
The outer core is about 1,400 miles thick, and it's made mostly of a combination (called an alloy) of iron and nickel, along with small amounts of other dense elements like gold, platinum, and uranium. These metals can, of course, be found on the surface of Earth in solid form.
what is the formula for selenium tetrafluoride
Answer:
SeF4
Explanation:
SeF4
Answer:
The anwser is SeF4
BRANLIEST AND 100 POINTS.
Compare and contrast the structure of yeast and algae.
Algae is a member of the Protista kingdom, a group of mostly aquatic photosynthetic organisms. Yeast, any one of roughly 1,500 species of single-celled fungi, the majority of which belong to the phylum Ascomycota with just a few Basidiomycota species.
What are characteristics of algae and yeast ?
Algae have a variety of life cycles and range in size from tiny micro species to giant kelps with lengths of up to 60 meters (200 feet).Their cells have characteristics that are unique to animals and plants, and their photosynthetic pigments are more diverse than those of plants. Algae are economically significant as a source of crude oil, a source of food, and a source of a number of pharmaceutical and industrial products for humans. In addition to their ecological roles as oxygen producers and the food base for almost all aquatic life, algae are also important economically. Algae's taxonomy is contentious and subject to rapid revision as new molecular data emerge. A phycologist is someone who studies algae, and the field of study is known as phycology.Yeast, any one of roughly 1,500 species of single-celled fungi, the majority of which belong to the phylum Ascomycota with just a few Basidiomycota species. Yeasts can be found in soils and on plant surfaces all over the world. They are especially common in sugary mediums like fruit nectar and flower nectar. There are hundreds of ascomycete yeast varieties with significant economic value. Select strains of Saccharomyces cerevisiae are the ones that are commonly used to make beer, wine, and bread. Some yeasts, like Candida albicans, Histoplasma, and Blastomyces, can be mild to dangerous to humans and other animals.To know more about algae and yeast check this:
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Drag each tile to the correct location.
Several properties of water are shown. Classify each property as a physical property or a chemical property.
can be split into hydrogen and oxygen
is liquid at room temperature
reacts with certain metals
has a density of 1.0 g/cm3
Physical
Chemical
Answer:
1) chemical property
2) physical property
3) chemical property
4) physical property
Explanation:
Physical properties:
Physical properties are those properties which can be measured without changing the composition of mater. We can observe the object and tell its physical properties like its texture, physical appearance, color, melting point, boiling point, odor, density etc.
Chemical properties:
Chemical properties involve chemical reaction or we can say that change is happen in mater during chemical reaction and the properties, we measured during this or as a result of this reaction is called chemical properties. Like flammability, toxicity, combustion, decomposition etc.
1) Water can split into hydrogen and oxygen
chemical property
2) water is liquid at room temperature
physical property
3) water react with certain metals
chemical property
4)The density of water is 1.0 g/cm³
physical property
Answer:
Simplified for PLATO Users : )
An earthquake is a physical process that most affects the -
Select one:
biosphere
lithosphere
atmosphere
hydrosphere
Answer:
lithoshpere
Explanation:
1. Which law is associated with inertia?
2. If you increase the force in an object what happens to the acceleration?
3. If you use the same force on a less massive object what happens to the acceleration?
4. Which law states force is dependent on the mass and acceleration of an object?
5. What causes an object to slowdown or speed-up?
1. Which law is associated with inertia?
2. If you increase the force in an object what happens to the acceleration?
3. If you use the same force on a less massive object what happens to the acceleration?
4. Which law states force is dependent on the mass and acceleration of an object?
5. What causes an object to slowdown or speed-up?
HOPE IT HELPS YOU
Please Help -
Complete the table
Answer:
Proteins
Elements: C, H, O, N, and some S
Monomer: amino acids
Functions: catalyzing chemical reactions, synthesizing and repairing DNA, structural support, transporting materials across the cell
Examples: hemoglobin, actin and myosin, albumin, keratin
Carbohydrates
Elements: C, H, O
Monomer: monosaccharides
Functions: cellular identity, source of energy, storage of energy, structural support, cell signaling, make ATP, convert solar energy
Examples: glucose, starch, glycogen, peptidoglycan, cellulose, chitin
Nucleic Acids
Elements: C, H, O, N, P
Monomer: nucleotides
Functions: storage and expression of genetic information, transmission of genetic code required for making proteins
Examples: DNA, RNA
Lipids
Elements: C, H, O, and some P and N
Monomer: fatty acids
Functions: energy storage, cell structure, insulation and protection, regulating and signaling, digestion
Examples: steroids (cholesterol), waxes, fats and oils, phospholipids
Hope that helps.
. The center of the atom is called the
(10 Points)
O nucleus
O protons
O electrons
O
neutrons
Answer:
Protons I think. I might be wrong but I think its Protons
Answer:
the nucleus is the center of atoms and its made of of protons and neutrons
Explanation:
What is the mass of Na?
2NaN3
2NaN3 2Na + 3N2
(500g) (?) (3235)
Answer:
its division
Explanation:
How does flame spread over liquid depend on the flash point?
4) How many grams of carbon dioxide would be needed to produce 3.382 grams of
acetylene (C2H,) using the following reaction?
4 CO2(g) + 2 H20(g) → 2 C2H2(g) +5 02(g)
Answer:
11.4 g CO₂
Explanation:
Your chemical equation is:
4 CO₂ + 2 H₂O ⇒ 2 C₂H₂ + 5 O₂
You need to produce 3.382 g of acetylene. To find out how many grams of carbon dioxide you need, first convert grams of acetylene to moles using the molar mass. The molar mass of acetylene is 26.04 g/mol.
(3.382 g)/(26.04 g/mol) = 0.130 mol C₂H₂
Now, use the mole ratio between acetylene and carbon dioxide to convert from moles of acetylene to moles of carbon dioxide. You can find the mole ratio by looking at the chemical equation. The mole ratio is (4 mol CO₂)/(2 mol C₂H₂).
(0.130 mol C₂H₂) × (4 mol CO₂)/(2 mol C₂H₂) = 0.260 mol CO₂
Since you now have moles of carbon dioxide, you can convert to grams using the molar mass. The molar mass of carbon dioxide is 44.01 g/mol.
0.260 mol × 44.01 g/mol = 11.4 g CO₂
You will need 11.4 g of CO₂ to produce 3.382 g of C₂H₂.
calculate the mass of ethyl chloride to form if 4.66 g of ethylene reacts with an 89.4 percent yield
Answer:
Explanation:
C₂H₄ + HCl = C₂H₅Cl
28 g 64.5 g
28 g of ethylene reacts to give 64.5 g of ethyl chloride
4.66 g of ethylene reacts to give 64.5 x 4.66 / 28 g of ethyl chloride
= 10.73g
yield = 89.4 %
ethyl chloride produced = 10.73 x .894
= 9.6 g .
Which particles are very far apart from each other are constantly moving and I have no definition shape or volume
Answer:
Gas particles
Explanation:
Particles in the gaseous state have the greatest amount of energy, they move around rapidly and they have large spaces between them
Which of the following can be observed without changing the identity of a substance? Select all that
apply.
Flammability
Reactivity
Density
Boiling point
Density can be observed without changing identity of a substance .
What is density?Density of a substance is defined as the mass of the substance mass per unit of volume. It is represented by a capital letter'D'. It is mathematically defined as mass divided by volume.
It is defined loosely as weight of substance per unit volume. It is scientifically inaccurate it is more specifically called as specific weight.Different substances have different densities and these are related to purity and buoyancy.
Osmium and iridium are the densest known elements. To simplify comparisons, it is replaced sometimes by a quantity which is dimensionless called relative density. Density of a material varies with temperature and pressure. The variation is small for solids and greater for gases. Increase in pressure increases the density.
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Improvements in which area would help reduce the possibility of damage to the environment when using uranium as a fuel?
A.more-efficient extraction techniques
B.better control of fusion reactions
C.stronger-pumping wells
D.thicker shielding around the reactor
Answer:
A is the answer; 'more-efficient extraction techniques
Explanation:
I just took the test and got it right :D
Answer:
A is the answer to the question
The positively charge subatomic particles that are located in the nucleus are called
(10 Points)
nucleus
protons
electrons
neutrons
Answer:
Protons
Explanation:
The nucleus contains two type of subatomic particles.