666
Explanation:
nhgytfghgtfgv
Is freeze-drying a physical change or chemical change?
Answer:
Physical change because it can go back to its original form.
Explanation:
(IM ONLY ALOWED TO GIVE 10 POINTS) Sound travels at a speed of 330 m/s. How long does it take for the sound of thunder to travel 1745 meters?
Group of answer choices
5.28 seconds
5.28 hours
575850 seconds
189 seconds
what are 4 ways a mineral can form
Answer:
The four main categories of mineral formation are: (1) igneous, or magmatic, in which minerals crystallize from a melt, (2) sedimentary, in which minerals are the result of sedimentation, a process whose raw materials are particles from other rocks that have undergone weathering or erosion, (3) metamorphic, in which new minerals form at the expense of earlier ones owing to the effects of changing—usually increasing—temperature or pressure or both on some existing rock type, and (4) hydrothermal, in which minerals are chemically precipitated from hot solutions within Earth.
The mineral can be formed from volcanic gases, oxidation, crystallization from magma, sediment formation, or deposition from a saline fluid.
What is a mineral?A rock can be described as a collection of minerals. A rock that becomes so hot it melts and many minerals come out in liquids that are hot enough to melt rocks.
Magma can be defined as a melted rock inside Earth, a molten mixture of substances that can be hot to more than 1,000°C. When the magma cools slowly inside the earth, which provides mineral crystals time to grow large enough.
Granite is a rock that produces from slowly cooled magma, consisting of the minerals quartz, plagioclase feldspar which is shiny white, pink potassium feldspar, and black biotite.
When magma will erupt onto the surface of the Earth, it is known as lava. Lava cools more rapidly than magma when it is below the surface and mineral crystals do not have time to form. But the chemical composition remains the same as if the magma cooled slowly.
The mineral can be formed through hydrothermal processes, weathering, and metamorphic and igneous environments.
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An open flask sitting in a lab fridge looks empty, but it is filled with a mixture of gases called air. Calculate the number of molecules of gas the flask contains if the flask volume is 2.50 L , and the air is at standard temperature and pressure (STP).
Answer: The number of molecules of gas the flask contains is [tex]0.674\times 10^{23}[/tex]
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1 atm (STP)
V = Volume of gas = 2.50 L
n = number of moles = ?
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature = 273K (STP)
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{1atm\times 2.50L}{0.0821 L atm/K mol\times 273K}=0.112moles[/tex]
According to Avogadro's law:
1 mole of gas at STP contains =[tex]6.023\times 10^{23}[/tex] molecules
Thus 0.112moles of gas at STP contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.112=0.674\times 10^{23}[/tex] molecules
The number of molecules of gas the flask contains is [tex]0.674\times 10^{23}[/tex]
Please help me I. Eg you
Answer:
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Explanation:
What are the oxidation numbers of the atoms in this reaction?
Check all that apply.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
0 for Mg in Mg and MgCl2
0 for Mg(s) and H in H2
+1 for H in HCl
-1 for Cl in HCl
+2 for Mg in MgCl2
Answer:
2-5
Explanation:
I just did it.
The oxidation numbers of the atoms in this reaction are 0 for Mg(s) and H in H₂, -1 for Cl in HCl, +1 for H in HCl and +2 for Mg in MgCl₂
What is oxidation number?An oxidation number is a number assigned to atoms in molecules to show the general distribution of the electrons.
Oxidation state or number helps us describe the transfer of electrons.
The oxidation number/state is also used to determine the changes that occur in redox reactions.
Overall, the oxidation number of an atom in a molecule is the charge that the atom would have if all polar covalent and ionic bonds resulted in a complete transfer of electrons from the less electronegative atom to the more electronegative one.
Therefore, The oxidation numbers of the atoms in this reaction are 0 for Mg(s) and H in H₂, -1 for Cl in HCl, +1 for H in HCl and +2 for Mg in MgCl₂
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1.) A laser emits light of frequency 3.72 x 1014 /s. What is the wavelength of the light in m?
2.) Calculate the energy, in joules, of a single photon associated with frequency of 4.00x105/s
3.) Determine the frequency and energy of a photon whose wavelength is 2.57x10-7 m
explanation and work needed please
Answer:
1. λ = 806nm
2. E = 2.6504 × 10^-28J
3. a) f = 1.167 × 10^15 Hz
b) E = 7.73 × 10^-19J
Explanation:
1) The wavelength denoted by λ can be calculated using the formula:
λ = v / f
Where;
v = speed of light (3×10^8m/s)
f = frequency of light (Hz)
λ = 3 × 10^8/3.72 x 1014
λ = 0.80645 × 10^(8-14)
λ = 0.80645 × 10^-6
λ = 8.06 × 10^-7m
λ = 806nm
2) The energy (J) of a photon is calculated thus;
E = hf
Where;
h = Planck's constant (6.626 × 10^-34J/s)
f = frequency (4.00x10^5/s)
E = 6.626 × 10^-34 × 4.00x10^5
E = 26.504 × 10^(-34+5)
E = 26.504 × 10^-29
E = 2.6504 × 10^-28J
3. λ = v / f
2.57x10^-7 = 3 × 10^8 ÷ f
f = 3 × 10^8/2.57x10^-7
f = 1.167 × 10^(8+7)
f = 1.167 × 10^15 Hz
b) E = hf
E = 6.626 × 10^-34 × 1.167 × 10^15
E = 7.7325 × 10^(-34+15)
E = 7.73 × 10^-19J
Which of the substances have polar interactions (dipole–dipole forces) between molecules?
A. Cl2
B. F2
C. ClF
D. NF3
Answer:
F2 and Cl2 are non-polar because both contains same atom and they have same electronegativity.
ClF and NF3 have polar interactions because there is electronegativity difference between atoms.
Explanation:
The covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule. Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas. The shared electron pair is common to the two atoms and holds them together.
Electronegativity is defined as the ability of an element to attract the electrons that link it to another element.
The covalent bond between two atoms can be polar or nonpolar.
When two atoms have different electronegativities, the one with the highest electronegativity will attract the electrons towards each other, giving rise to two opposite charges on the bond. That is, this generates that in a polar molecule there is separation between positive and negative charges. The bonds will be all the more polar the greater the difference in electronegativity between the bound atoms.
On the other hand, the non-polar covalent bond occurs between atoms of the same element or between atoms with very little electronegativity difference. It is thus characterized to molecules or bonds that do not exhibit any polarity.
A molecule is a dipole when there is an asymmetric distribution of electrons because the molecule is made up of atoms of different electronegativity. That is, dipole is formed when the molecule is polar.
So, dipole-dipole forces are forces of attraction between polar molecules. These molecules attract when the positive end of one of them is close to the negative of the other.
Given the above, F₂ and Cl₂ are non-polar molecules and ClF and NF₃ are polar molecules. Then ClF and NF₃ have polar interactions (dipole-dipole forces). -Brainly user
Hope this helps!The density of a substance is 1.63 grams per milliliter. What is the volume, in ml, of a sample of the substance with a mass of 5.40Kg? 1000 g = 1 kg
Answer:
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Explanation:
What volume, in L, of a 6.3 M K2SO4 solution contains 44.1 g of K2SO4?
11) Nitrogen oxides undergo many interesting reactions in the environment and in industry. Given the following information, calculate H for the overall equation:
2 NO2(g) + 1/2 O2(g) N2O5(s).
N2O5(s) 2 NO(g) + 3/2 O2(g), deltaH = 223.7 kJ
NO2(g) NO(g) + 1/2 O2(g), delataH = 57.1 kJ
delataH = ______kJ
12))))Write all coefficients, even if they are fractions or 1.)
(a) (Apply fractions as needed.)
______ _____(s) + ______ ______ (g) 5 NaCl(s)
(b) (Use the lowest possible coefficients.)
_______ _____ (s) + ______ _____(g) _____CaCl2(s)
(c) (Apply fractions as needed.)
_____ _____(g) _____O3(g)
(d) (Apply fractions as needed.)
______Mg(s) + _____ ______(s) + _____ ____(g) _____Mg3(PO4)2(s)
Answer:
one more time
Explanation:
shpuld i go
Which of these electron transitions correspond to absorption of energy and which to emission?
a. n = 5 to n = 6 absorption emission
b. n = 9 to n = 6 absorption emission
c. n = 6 to n = 4 absorption emission
d. n = 6 to n = 7 absorption emission
Answer:
n = 5 to n = 6 absorption
n = 9 to n = 6 emission
n = 6 to n = 4 emission
n = 6 to n = 7 absorption
Explanation:
According to the Bohr's model of the atom. An electron in an atom may absorb energy and move from a lower energy level to a higher energy level. This requires absorption of energy that is equal to the energy difference between the two levels.
Similarly, an electron may move from a higher to a lower energy level, releasing energy that is equal to the energy difference between the higher and the lower level. This is known as emission.
Hence, if the electron is moving from a lower energy level to a higher energy level, an absorption has taken place, e.g n = 5 to n = 6
When an electron moves from a higher energy level to a lower energy level, an emission has taken place e.g n = 9 to n = 6
What two subatomic particles add up to make the mass?
How many mL (to the nearest mL) of 0.140-M KF solution should be added to 400. mL of 0.212-M HF to prepare a pH
Answer:
205mL of 0.140M KF solution
Explanation:
pH = 2.70 solution.
It is possible to obtain the pH of the buffer of HF-KF using the H-H equation:
pH = pKa + log [KF] / [HF]
Where pH is desire pH = 2.70
pKa is pKa of HF = 3.17
[KF] could be taken as moles of KF
And [HF] moles of HF: 400.0mL = 0.4L * (0.212mol/L) = 0.0848 moles of HF
Replacing:
2.70 = 3.17 + log [KF] / [0.0848 moles HF]
-0.47 = log [KF] / [0.0848 moles HF]
0.3388 = [KF] / [0.0848 moles HF]
[KF] = 0.02873 moles of KF must be added.
In mL using concentration of KF (0.140M):
0.02873 moles KF * (1L / 0.140 mol) = 0.205L =
205mL of 0.140M KF solutionlimnetic, profundel, littoral, and benefitic have what in common
trioxocarbonate iv acid
Answer:
Trioxocarbonate (iv) are salts derived from trioxocarbonate (iv) acid when it reacts with metals and metallic oxides. All trioxocarbonate (iv) salts of Sodium (Na), Potassium (K) and Ammonium(NH4+) are soluble while all others are insoluble.
Please help. Will give brainliest.
Answer:
B.
Explanation:
i think its B
Why aren't the masses on the periodic table whole numbers?
The compound potassium carbonate is a strong electrolyte. Write the reaction when solid potassium carbonate is put into water
Answer:
K2CO3 (aq) ---> 2K+ (aq) + CO32- (aq)
Explanation:
Dissociation refers to the ability of an ionic compound to breakdown into its respective ions. An ionic compound is formed by the combination of a positive ion (cation) and a negative ion (anion). When these ionic compound dissolves in water, it dissociates i.e. separates into its constituent ions.
In this question involving potassium carbonate being described as a strong electrolyte, which means that it dissociates completely in water as follows:
K2CO3 (aq) ---> 2K+ (aq) + CO32- (aq)
A sample is found to contain 2.98x10^-10 g of salt. Express this quantity in nanograms.
This quantity = 0.298 nanograms(ng)
Further explanationMass is one of the principal quantities, which is related to the matter in the object
The main mass unit consists of 7 units of other than other units of mass such as quintals, tons, pounds, ounces:
Kilogram, kg
Hectogram, hg
Decagram, dag
gram, g
Desigram, with
centigram, cg
milligram, mg
Each unit descends then multiplied by 10, and if one unit increases then divided by 10
Conversion of other mass units:
10⁻³ g ⇒mg-milligrams
10³ g ⇒kg-kilograms
10⁻⁶ g ⇒µg-micrograms (mcg)
10⁶ g ⇒Mg-megagrams (tons)
10⁻⁹ g ⇒ng-nanograms
10⁹ g ⇒Gg-gigagram
10⁻¹² g ⇒pg-pikogram
2.98 x 10⁻¹⁰ g to nanograms(ng)
[tex]\tt 2.98\times 10^{-10}\times 10^9=0.298~ng[/tex]
What is laughing gas?
Answer:
Nitrous oxide, commonly known as laughing gas or nitrous, is a chemical compound, an oxide of nitrogen with the formula N ₂O. At room temperature, it is a colourless non-flammable gas, with a slight metallic scent and taste. At elevated temperatures, nitrous oxide is a powerful oxidiser similar to molecular oxygen.
Explanation:
HURRY PLEASE HELP
Four students are discussing the benefits and problems associated with using nuclear energy as alternative energy source. Which student has the strongest argument about using nuclear energy?
A. Nuclear power plants pollute the environment and causes cancer in populations that use nuclear energy instead of traditional electricity.
B. Nuclear power plants provide more energy than traditional coal plants; however, nuclear power plants also produce more greenhouse gases.
C. Nuclear power plants run a high risk of nuclear meltdown killing all the organisms in a 20 mile radius.
D. Nuclear power plants provide more energy than traditional coal plants and these plants do not produce greenhouse gases.
Answer:
A
Explanation:
its A
facts o.o
Nuclear power plants pollute the environment and causes cancer in populations that use nuclear energy instead of traditional electricity. Hence option A is correct.
What is nuclear power plant?Nuclear power plant is defined as a particular kind of power plant that produces electricity by nuclear fission. Nuclear power plants use the heat generated by nuclear fission to transform water into steam in a controlled environment, which then powers generators to produce electricity. Low-enriched uranium fuel is used in nuclear power plants to generate electricity through a process known as fission, which involves breaking uranium atoms in a nuclear reactor.
A clean energy source with no emissions is nuclear. It produces energy by fission, which is the splitting of uranium atoms to release energy. Without the toxic consequences that come from burning fossil fuels, electricity is produced using the heat from fission to produce steam, which turns a turbine.
Thus, nuclear power plants pollute the environment and causes cancer in populations that use nuclear energy instead of traditional electricity. Hence option A is correct.
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15
4
(3.2)
52
2
1 2 3 4 5
(4) OX
Z
(2.-25
3
5
Based on the graph, the coordinates for Do. 1 of X are:
O (4,0)
O (5, 1)
O (3.-1)
0.954 mol bromine is added to 1 L reaction vessel that contains 1.22 mole of hydrogen and 1 mole of HBr at 1500K. What is the partial pressure of hydrogen, bromine and HBr at equilibrium?
Answer:
Partial pressure of H₂ → 149.9 atm
Partial pressure of Br₂ → 117.2 atm
Partial pressure of HBr → 112.8 atm
Explanation:
The problem can be solved by the Ideal Gases Law.
In a mixture of gases we know that the sum of partial pressures values the total pressure in the vessel. And the total pressure in the vessel is generated by the total moles which are presennt.
Total moles = 0.954 moles + 1.22 moles + 1 mol = 3.174 moles
Let's apply the Law to determine the total pressure.
P . 1 L = 3.174 moles . 0.082 . 1500 K
P = 390.4 atm
Now we apply the mole fraction concept
Mole fraction (1) → moles of gas / total moles
Mole fraction (2) → partial pressure of gas / total pressure
In conclussion 1 = 2
Partial pressure of H₂ → (1.22 / 3.174) . 390.4 atm = 149.9 atm
Partial pressure of Br₂ → (0.954 / 3.174) . 390.4 atm = 117.2 atm
Partial pressure of HBr → (1 / 3.174) . 390.4 atm = 112.8 atm
How does the number of atoms or molecules in a system affect its thermal energy?
A. A system with fewer atoms and molecules has more thermal energy.
B. A system with more atoms and molecules has more thermal energy.
C. The number of atoms or molecules does not affect the thermal energy of a system.
D. Thermal energy increases as the atoms and molecules in a system move more.
Answer:
D. Thermal energy increases as the atoms and molecules in a system move more.
Explanation:
Thermal energy is a form of kinetic energy possessed by molecules of a system. The measure of this kinetic energy in an atom is called heat.
The average kinetic energy of a system is the temperature.
According to the kinetic theory, the more the particles move, the more their thermal energy. Thermal energy is often predicated on the velocity of the particles of the medium.9.
Which of the following molecules has (have) polar bonds?
a water
b carbon dioxide
c formaldehyde
d two of the above
Answer:
two of the above
Explanation:
cK-12 Bond Polarity
Which statement about hydrogen bonds is true?
Explanation:
Hydrogen bond is a type of intermolecular chemical bond formed between two molecules. It is classified as a special dipole-dipole attraction between polar molecules in which a hydrogen atoms is directly joined to a highly electronegative atom.
A hydrogen nucleus has a high concentration of positive charges. A hydrogen bond is actually an electrostatic attraction between the hydrogen atom (nucleus of one molecule and the electronegative atom, O or N or F) of a neighboring molecule. The strength of the bond depends on the relative electronegativity of the atom directly joined to the hydrogen. Hydrogen bonding forces is reflected in the physical properties of compounds such as water and ammonia.The proportion of the electronegativity of an atom that is directly hydrogen bonded to the hydrogen determines how strong the connection will be. This statement is true about hydrogen bonds.
An intermolecular chemical interaction known as a hydrogen bond is created when two molecules come together. When a hydrogen atom is linked directly to an atom that has a strong electronegative potential, it is categorised as a specific case of dipole-dipole attraction among polar molecules.
A hydrogen bond is essentially an electrostatic attraction among a neighbouring molecule's O, N, or F atom and its hydrogen atom, which is the nucleus of one of the molecules.
The proportion of the electronegativity of an atom that is directly bonded to the hydrogen determines how strong the connection will be.
Compounds like water and ammonia have physical characteristics that are influenced by hydrogen bonding forces.
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the illustration shows how sonar can be used to study the deep ocean which type of waves does sonar use
Answer:
d
Explanation:
The definition of having to do with the physical properties and terrain of an area refers to the
term
environmental
forecasting
meticulous
topographical
adjacent
Answer:
Topographical
Explanation:
When it comes to questions such as this one, the thing that could help you the most is a dictionary. A dictionary is an alphabetically arranged listing of words that contains various information about those words, such as their definitions, examples, origin, pronunciation, etc.
The term the given definition refers to is topographical. Topography is the study of the forms and features of land surfaces. The topography of an area refers to its physical properties and terrain or their description (e.g. how they're shown on a map).
How many grams of methionine (MW = 149.21) are needed to make 20 mL of a 150 mM solution?
Answer:
0.45 g
Explanation:
Step 1: Given data
Molar mass of methionine (M): 149.21 g/molVolume of the solution (V): 20 mLConcentration of the solution (C): 150 mMStep 2: Calculate the moles of methionine (n)
We will use the following expression.
n = C × V
n = 150 × 10⁻³ mol/L × 20 × 10⁻³ L
n = 3.0 × 10⁻³ mol
Step 3: Calculate the mass of methionine (m)
We will use the following expression.
m = n × M
m = 3.0 × 10⁻³ mol × 149.21 g/mol
m = 0.45 g