Answer:
Wavelength (λ) = 1.875 × 10⁻⁶ m
Explanation:
Given:
Energy (e) = 1.06 × 10⁻¹⁹ J
Find:
Wavelength (λ) = ?
Computation:
e = hc / λ
λ = hc / e
where c = 3 × 10⁸
Planck's constant (h) = 6.625 × 10⁻³⁴
So,
Wavelength (λ) = (6.625 × 10⁻³⁴)(3 × 10⁸) / (1.06 × 10⁻¹⁹)
1. Wavelength (λ) = 1.875 × 10⁻⁶ m
2. Given n = 4 to n = 3 both are integer not fraction so, electron is quantize
D. Answer these questions.
1. What is chemistry?
2. What is scientific method?
Answer:
1.Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.
2.The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observations.
List down the observations made by Rutherford during the gold foil experiment.
Answer:
1) The volume occupied by an atom is composed of mainly empty space
2) Atoms have a very small, relatively dense, central nucleus that is positively charged
3) The region around the nucleus of an atom are orbited by negatively charged electrons in a the same fashion planets orbit around the Sun.
Explanation:
The selection of gold for the gold foil experiment was due to its ability to be rolled into extremely thin sheets such that it was expected for alpha particle to perforate or pass through the foil.
fill in the blanks with the words given below-
[Atoms, homogeneous, metals, true, saturated, homogeneous, colloidal, compounds, lustrous]
1.An element which are sonorous are called................
2.An element is made up of only one kind of ....................
3.Alloys are ............................. mixtures.
4.Elements chemically combines in fixed proportion to form ........................
5. Metals are................................... and can be polished.
6. a solution in which no more solute can be dissolved is called a .................... solution.
7. Milk is a .............. solution but vinegar is a .................. solution.
8. A solution is a ................... mixture.
pls help, could not get these answers
Answer:
1. Metal.
2. Atom.
3. Homogeneous
4. Compounds.
5. Lustrous
6. Saturated.
7. Colloidal; true.
8. Homogeneous.
Explanation:
1. An element which are sonorous are called metal.
2. An element is made up of only one kind of atom.
3. Alloys are homogeneous mixtures.
4. Elements chemically combines in fixed proportion to form compounds.
5. Metals are lustrous and can be polished.
6. A solution in which no more solute can be dissolved is called a saturated solution.
7. Milk is a colloidal solution but vinegar is a true solution.
8. A solution is a homogeneous mixture.
One to two paragraphs describing the water cycle
Answer:
The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. This repeats again and again in a never-ending cycle. Water keeps moving and changing from a solid to a liquid to a gas, over and over again.
Precipitation creates runoff that travels over the ground surface and helps to fill lakes and rivers. It also percolates or moves downward through openings in the soil to replenish aquifers under the ground. Some places receive more precipitation than others do. These areas are usually close to oceans or large bodies of water that allow more water to evaporate and form clouds. Other areas receive less precipitation. Often these areas are far from water or near mountains. As clouds move up and over mountains, the water vapor condenses to form precipitation and freezes. Snow falls on the peaks.
The continual movement of water on, above, and below the Earth's surface is referred to as the water cycle, also known as the hydrological cycle.
What is water cycle ?The water cycle demonstrates how water is constantly moving both inside the Earth and in the atmosphere. It is a complicated system with a wide range of processes.
Water vapor is created when liquid water evaporates, and this water vapor then condenses to form clouds and falls back to earth as rain and snow.
The constant flow of water between the ground and the atmosphere is known as the water cycle. Water travels to land as precipitation, like snow and rain.
The cycle is then completed by the water evaporating, condensing into clouds in the atmosphere, and precipitating once more on earth. The water cycle is composed mostly of four processes: evaporation, convection, precipitation, and collection.
Thus, The continual movement of water on, above, and below the Earth's surface is referred to as the water cycle.
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Can a window pane be considered a mineral?
Answer:
Explanation:
The glass (which does not crystallize even though it is accepted) of a window is NOT a mineral, since it is neither a substance of natural origin (although it is manufactured from natural components) nor does it have a defined crystalline structure, that is, the atoms they are not arranged in an orderly and regular way along axes and planes forming flat faces that keep a symmetry.
Remember that a mineral is defined as a solid, inorganic, homogeneous substance, of natural origin, with a crystalline structure and a determined and well-defined chemical composition within narrow margins and that has regular and characteristic physical properties.
Explanation: No, glass is not a mineral. ... Definable chemical composition: SiO2 *Actually, most industrially-produced glass is not pure silica, but having impurities is still a definable chemical composition so this part of the definition is ok. Orderly arrangement of atoms in a lattice: NO.
WILL GIVE BRAINLIEST, Which of the following would have the greatest amount of surface area?
A. 1 cubic foot of watermelons
B. 1 cubic foot of matchbox cars
C. 1 cubic foot of loose sand
D. A 1 cubic foot block of concrete
Answer:
C. 1 cubic foot of loose sand
Explanation:
For many objects having equal volume , surface area will be maximum
of the object which has spherical shape .
But when a sphere is broken into tiny small spheres , total surface area of all the small spheres will be more than surface area of big sphere .
Hence among the given option , surface area of loose sand will have greatest surface area . Loose sand is equivalent to small spheres .
Answer:
the answer would be C 1 cubic foot of loose sand.
2.A helium-filled balloon has a
volume of 48.0 L at 25°C and
1.05 atm. What volume will it
have at 0.860 atm and 15°C?
Answer:
The volume at 0.860 atm and 15°C will be 56.638 L
Explanation:
Gay Lussac's law explains the variation in the pressure of a gas by modifying its temperature, keeping the volume constant: it determines that pressure and temperature are directly proportional quantities. In other words, Gay-Lussac's law states that when a gas undergoes a constant volume transformation, the ratio of the pressure exerted by the temperature of the gas remains constant:
[tex]\frac{P}{T}=k[/tex]
On the other hand, Boyle's law determines that the pressure exerted by a gas is inversely proportional to its volume at constant temperature. This is expressed mathematically as:
P*V=k
Finally, Charles's law says that at constant pressure, the volume of an ideal gas is directly proportional to its absolute temperature and is expressed mathematically as:
[tex]\frac{V}{T}=k[/tex]
Combined law equation is the combination of three gas laws called Boyle's, Charles's and Gay-Lussac's law:
[tex]\frac{P*V}{T}=k[/tex]
When you want to study two different states, an initial one and a final one of a gas, you use:
[tex]\frac{P1*V1}{T1}=\frac{P2*V2}{T2}[/tex]
In this case:
P1= 1.05 atmV1= 48 LT1= 25 C= 298 K (being 0 C= 273 K)P2= 0.86 atmV2= ?T2= 15 C= 288 KReplacing:
[tex]\frac{1.05 atm*48 L}{298 K}=\frac{0.86atm*V2}{288 K}[/tex]
and solving:
[tex]V2=\frac{288 K}{0.86 atm} *\frac{1.05 atm*48 L}{298 K}[/tex]
you get:
V2= 56.638 L
The volume at 0.860 atm and 15°C will be 56.638 L
4. (01.05 MC)
Rubbing alcohol evaporates from your arm quickly, leaving a cooling effect on your skin. How do the molecules of gas compare to the molecules as a liquid? (4 points)
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
The gas particles move faster than the liquid particles, and the bonds of the molecules are broken during evaporation to allow gas atoms to spread apart.
The gas particles move slower but have the same molecular structure and the same attraction between them as the liquid particles.
The gas and liquid particles move at the same speed, but the bonds of the molecules are broken during evaporation to allow the gas atoms to spread apart
Answer:
The correct option is;
The gas particles move faster, have the same molecular composition, and have weaker attractions between them than the liquid particles
Explanation:
The properties of the gas molecules in comparison to liquids are
1) The gas molecules are widely spread out
2) After evaporation and while in conditions favorable to the gaseous state, the kinetic energy of a gas is larger than the inter molecular attractive forces
3) A gas fills the container in which it is placed
For liquids
1) There are strong intermolecular forces holding the molecules together in a liquid
2) Liquid attractive forces in a liquid are strong enough to hold neighboring molecules
3) The volume of a liquid is definite.
How many moles of lithium are in 83 grams of lithium? pls answer :(
Explanation:
89cjowdncu8wncuhrwionu9wjvionajofhjowednuiw4fmji2rn most jom4opr
Answer it answer it answer it
Answer:
[tex]\Large \boxed{\mathrm{A}}[/tex]
Explanation:
Rust formed from iron and oxygen combining is a chemical change, because in a chemical change, the resulting substance(s) will have different properties from the substance(s) before the chemical change.
I cant comment... So is it Right?
The number of atoms in 2.0 moles of NaOH is _____ of 1.0 mole of H2O.
twice that
less than
more than
the same as
Answer:
The answer is the same as .
Explanation:
There are 3 atoms in NaOH, 1 sodium, 1 oxygen and 1 hydrogen.
There are 3 atoms in H2O, 2 hydrogen and 1 oxygen.
the overall take away of an experiment’s results is the______. A. hypothesis B. introduction C. conclusion
Answer:
conclusion
Explanation:
it can't be a hypothesis since tests are carried out to verify so it is not a theory
an introduction to an experiment only gives the basis of what we are investigating therefore nothing has been proven and the question is still unanswered
The overall takeaway of an experiment’s results is the conclusion. Hence, option C is correct.
What is a hypothesis?A hypothesis is a testable statement about the relationship between two or more variables or a proposed explanation for some observed experiment.
The overall takeaway of an experiment’s results can't be a hypothesis since tests are carried out to verify so it is not a theory
An experiment only gives an idea about the investigation therefore nothing has been proven and the question is still unanswered.
Hence, the overall takeaway of an experiment’s results is the conclusion.
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formula for soda glass
Answer:
composition of soda-lime glass is 73% SiO2 – 15% Na2O − 7% CaO − 4% MgO − 1% Al2O3 [129,132,133].
The Soda glass formula is SiO2, Na2O, CaO, Al2O3, K2O, SO3, MgO, Fe2O3, TiO2
Soda glass is a chemical compound that stands out for being the most widely used material to make windows, bottles, glasses, among others.
This compound is characterized by being chemically stable, reasonably hard, and extremely versatile because it can be recycled since it can be melted to make new products.
Its chemical formula is made up of other compounds such as:
SiO2, is Silicon OxideNa2O, is sodium oxideCaO, is calcium oxideAl2O3, is aluminum oxideK2O, is potassium oxideSO3, is sulfur oxideMgO, is magnesium oxideFe2O3, is iron oxideTiO2, is Titanium OxideAdditionally, the compounds found in the highest proportion in glass are SiO2 (74 atoms) and Na2O (13 atoms).
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Se someten a combustion 0,452g de un compuesto de C,H y N de masa molecular 80. Al recoger el CO2 y el H2O producidas obtenemos 0,994 g y 0,203 respectivamente. Determine formula empirica y formula molecular
Answer:
Fórmula empírica: C₂H₂N
Fórmula molecular: C₄H₄N₂
Explanation:
Un compuesto que contiene carbono hidrógeno y nitrógeno con fórmula CₐHₓNₙ es sometido a combustion produciendo:
CₐHₓNₙ + O₂ → aCO₂ + x/2 H₂O + nNO₂
Con la masa de dióxido de carbono y agua podemos encontrar las moles de carbono e hidrógeno y su aporte a los 0.452g de muestra que fueron puestos en combustión, así:
Moles C:
Moles C = Moles CO₂ = 0.994g CO₂ ₓ (1mol / 44g) = 0.0226 moles C
Masa C: 0.0226 moles C ₓ (12.01g / mol) = 0.271g Carbono hay en la muestra
Moles H:
Moles H = 2 Moles H₂O = 0.203g H₂O ₓ (1mol / 18g) = 0.0113 moles H₂O = 0.0226 moles H
Masa H: 0.0226 moles H ₓ (1.01g / mol) = 0.023g Hidrógeno hay en la muestra
Así, la masa de nitrógeno en la muestra y sus moles son:
Masa N = 0.452g - 0.271g C - 0.023g H
Masa N = 0.158g Nitrógeno
Y su moles son:
0.158g ₓ (1 mol / 14.01g) = 0.0113 moles N
Con las moles de C, H y N podemos determinar la formula empírica que se define como: "La relación de números enteros más simple entre la cantidad de átomos presentes en una mólecula. Si usamos como base las moles de nitrógeno (Valor menor):
Relación H/N: 0.0226 mol / 0.0113 mol = 2
Relación C/N: 0.0226 mol / 0.0113 mol = 2
Relación N/N: 0.0113 mol / 0.0113 mol = 1
Así, la fórmula empírica es:
C₂H₂NEsta fórmula empírica tiene una masa molar de:
2C = 2*12 g/mol = 24g/mol
2H = 2*1g/mol = 2g/mol
N = 14g/mol
24+14+2 = 40g/mol
Como la masa molecular del compuesto es 80g/mol (Dos veces la de la fórmula empírica, la fórmula molecular es 2 veces la fórmula empírica:
C₄H₄N₂what is a disavanege for renewable solor power
How many protons does an atom of zinc contain?
It contains an amount
a single neutral atom of zinc has 30 protons
Mike wants to galvanize iron to protect it from rusting. Which metal should he use?
A
platinum
B.
aluminum
C.
copper
D.
zinc
E.
tungsten
Answer:
D. Zinc.
Explanation:
Galvanization is a metal-coating process which involves the application of a thin layer of zinc to an iron or steel, so as to prevent rusting or corrosion.
The zinc metal protects the iron from rusting by sealing the surface of the iron and thus, preventing weathering and oxidation.
Hence, if Mike wants to galvanize iron to protect it from rusting. The metal he should use is zinc (Zn) because a coating of zinc would protect the iron (Fe) by corroding first when exposed to moisture or the atmosphere.
Answer:
b
Explanation:
An event planner accidentally leaves a tray of cupcakes in his car for several hours on a sunny day. When he returns, the formerly firm frosting is now runny and wet to the touch. Which answer choice best describes what happened in this scenario? The particles of frosting released energy to their surroundings and changed from the solid to the liquid state. The particles of frosting released energy to their surroundings and changed from the liquid to the solid state. The particles of frosting absorbed energy from their surroundings and changed from the solid to the liquid state. The particles of frosting absorbed energy from their surroundings and changed from the liquid to the solid state.
Answer:
The particles of frosting absorbed energy from their surroundings and changed from the solid to the liquid state.
Explanation:
On a sunny day, the energy of the particles in the surrounding is higher than the energy of the frosting tray of cupcakes.
As a result of the exchange of energy between the tray of cupcakes and the surrounding, the tray of cupcakes absorbs energy from the surrounding. When this occurs, the firm frosting is now converted from solid to liquid which is runny and wet to touch, hence the answer above.
am gonna cry plz answer Which is not an inter molecular force? Select one: a. Inter atomic bonds b. van der waals forces c. hydrogen bonds
Answer:
inter atomic bonds
Explanation:
because it is loosely held
What is the formula of the ion hydrogen sulfite, which has a charge of -1
There are two types of ions in chemistry, one is cation and the other is anion. Anion is the negative charge ion. Therefore, the formula of hydrogen sulfite ion is HSO₃⁻
What is chemical Compound?Chemical Compound is a combination of ions, ions forms by combination of element and element forms by combination of atoms in fixed proportion.
According to our question the chemical compound from which hydrogen sulfite ion is coming is sulfurous acid that is H₂SO₃. So to get hydrogen sulfite ion we need to remove one hydrogen ion that is H⁺ from the chemical compound sulfurous acid.
The balanced reaction is
H₂SO₃[tex]\rightarrow[/tex]H⁺ + HSO₃⁻
From above reaction we can see that the charge over hydrogen sulfite ion is -1
Therefore the formula of hydrogen sulfite is HSO3-
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An atom of nitrogen has seven electrons. Which diagram correctly represents the arrangement of these electrons?
ОА.
OB
1112
1s 11:28 1111
2p
1s 12
2p
1s 12
12s 2p
OD. 1111s 112s
112p
Ос.
Answer:
Option C.
Explanation:
The arrangement of electrons in their orbital follows certain rules.
The Hund's rule practically explained how electrons are distributed in their orbitals.
The Hund's rule states that electrons distributed among the orbitals of the same shell singly (without partner) before pairing occurs.
In the filling of these electrons in their orbitals, we fill in the electron without pairing first because electrons tends to repel each other before filling with the opposite spin as shown in the attached photo.
Which statement best describes a compound formed by an ionic bond?
A) negatively charged
B) neutral
C) contains multiple charges
D) positively charged
Answer is D
Explanation:
Answer:
B. Neutral
Explanation:
When there is a ionic bond, one element steals or takes away an electron from the other element.
An example is NaCl
In this compound, Chlorine atom steals an extra electron from Sodium to fill its outer shell. So, this is a Ionic bond. Since, the Sodium compound gives away an atom, it is positively charged. Since, Chlorine steals an atom, it is negatively charged. Opposite charges attract, so they become a compound.
When positive and negative mix, it becomes neutral.
0.10 moles of sodium sulfate is dissolved into 12 mL of solution. What is the molar concentration of the solution?
Your answer should have two significant figures (round your answer to one decimal place).
the molar concentration should be atleast 5mL off the solution since its disolved
Answer:
8.3
Explanation:
Convert mL to L.
12 mL×1 L1000 mL=0.012 L
Solve for molarity.
Molarity=moles of solute
liters of solution=0.10 mol0.012 L=8.3 M
what is an example of mechanical energy converting to heat energy?
Answer:
Rubbing your hands together converts mechanical energy to thermal energy. Turning on a light switch converts mechanical energy to electrical and radiant energy.
When might Accurate length measurement be important?
Answer:
When you are going to measure small lengths or objects or when you are going to measure things with great accuracy.
Explanation:
oxidation number of Fe in Fe2(CO3)2
Answer:
+2
Explanation:
Oxidation number of an element, also called its oxidation state, is the number of electrons its atoms lost or gain in the process of forming a chemical compound.
To determine the oxidation state of an element or compound;
- The sum of all the oxidation numbers in a neutral compound must equal zero (0).
In the compound: Fe2(CO3)2
This compound is a neutral one, hence, its oxidation state is equal to zero (0).
It contains a polyatomic ion (carbonate ion) i.e. CO3 2-, whose net charge is -2.
Hence, to find the oxidation number of Iron (Fe), which is represented by X, in the compound, we say;
X(2) + -2(2) = 0
2X + -4 = 0
2X - 4 = 0
2X = 4
X = +2
Therefore, the oxidation number of Fe in Fe2(CO3)2 is (+2)
The compound Fe2(CO3)2 is called Iron (II) carbonate
Oxidation number of Fe in [tex]\rm Fe_2(CO_3)_2[/tex] is 2. An atom's oxidation number is a positive or negative number.
A notion used in chemistry to characterise the relative electron distribution and the level of oxidation or reduction of atoms in a compound or ion is known as the "oxidation number," sometimes known as the "oxidation state." Based on the presumption that electrons in chemical bonds are entirely transmitted to the more electronegative atom, it is a method of bookkeeping that assigns a notional charge to each individual atom in a molecule or ion.
The -4 stands for the overall charge that the carbonate ions provided, and the x is the Fe's oxidation number.
2x + (-4) = 0
2x - 4 = 0
2x = 4
x = 4/2
x = 2
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how will you measure the length of a curved line by using a thread?
A mixture of reactants and products for the reaction shown below is at
equilibrium in a 2.0 L container. What would most likely happen to the
equilibrium if the volume of the container were increased to 4.0 L?
N.(g) + 3H2(g)
22NH3(g)
Answer:
The system will shift to the left producing more moles of gases trying to maintain the original pressure of the system
Explanation:
Based on LeChatelier's principle, a change in temperature, pressure, volume or concentration on a system result in an opposing change trying to maintain the initial equilibrium conditions.
In the reaction:
N₂(g) + 3H₂(g) ⇄ 2NH₃(g)
4 moles of gas reacts producing 2 moles of gas.
In a gas reaction, the system will try to maintain the total pressure.
If the volume of the container increases, the system will shift to the side of the reaction that has more moles of gases in order to maintain the pressure.
That means if in the reaction the volume of the container increase from 2.0L to 4.0L the system will shift to the left producing more moles of gases trying to maintain the original pressure of the system.
pls balance the following chemical equation asap; Ca(OH)2 +CO2 = CaCO3+ H2O pls make it step by step
Answer:
Explanation:
Start by writing water as HOH
Ca(OH)2 +CO2 = CaCO3+ HOH
Next pay attention to the CO2 going to CO3
We need an oxygen.
Fortunately that is provided by the (OH)2
Now we have
Ca(OH)2 + CO2 ==> CaCO3 + HOH
and believe it or not, that is balanced as it is
The left side has 1 Ca. So does the right side
The Left side has 1 C. So does the right side.
The left side has 2 H. So does the right side
The left side has 2 oxygens (in Ca(OH2)) + 2 oxygens in CO2
So the equation is balanced.
Which correctly describe a reversible reaction reaching equilibrium in a closed system?
Select two that apply.
-Over time, the rates of the forward and reverse reactions equalize.
-Over time, the rate of the forward reaction becomes zero.
-Initially, the concentration of reactants is low, so the rate of the forward reaction is also low.
-Initially, the concentration of products is low, so the rate of the reverse reaction is also low.
-Over time, the rate of the reverse reaction becomes greater than the forward reaction.
Answer:
-Over time, the rates of the forward and reverse reactions equalize.
-Initially, the concentration of products is low, so the rate of the reverse reaction is also low.
Explanation:
A chemical reaction is said to be reversible when the reactants forms the products, which in turn reacts together again to give rise to the reactants. In a reversible reaction, the formation of products from reactants occurs simultaneously with the reformation of the reactants from the products. For example:
The reversible reaction: A + B ⇆ C + D means;
A + B → C + D and C + D → A + B
The rate at which both forward and reverse reactions are taking place in closed system may be initially different but with time, it gets equal to form an equilibrium reaction. However, at first, only the rate of the forward reaction proceeds because the concentration of the product is low. Hence, the rate of reaction of the reverse reaction (product to reactants) is low as well.
In the reversible reaction above, the rate of the reverse reaction (C + D → A + B) will turn out low initially because the concentration of the products (C and D) are low. With time, the rates of the forward and reverse reaction becomes equal to form an EQUILIBRIUM or STABLE reaction.
