need help with these three questions!!!​

Answer:

521 nm

Explanation:

From the question given above, the following data were obtained:

Frequency (v) = 5.76×10¹⁴ s¯¹.

Wavelength (λ) =.?

RECALL: velocity (c) of light = 3×10⁸ m/s

Thus, we can obtain the wavelength of the green light by using the following formula:

c = vλ

3×10⁸ = 5.76×10¹⁴ × λ

Divide both side by 5.76×10¹⁴

λ = 3×10⁸ / 5.76×10¹⁴

λ = 5.21×10¯⁷ m

Next, we shall convert 5.21×10¯⁷ m to nanometer (nm). This can be obtained as follow:

1 m = 1×10⁹ nm

Therefore,

5.21×10¯⁷ m = 5.21×10¯⁷ m × 1×10⁹ nm / 1 m

5.21×10¯⁷ m = 521 nm

Thus, 5.21×10¯⁷ m is equivalent to 521 nm

Therefore, the wavelength (λ) of the photon of the green light is 521 nm.

Answer:

the wavelength (λ) of the photon of the green light is 521 nm.

The empirical formula of the compound is C₃H₄O₂

From the question given above, the following data were obtained:

Carbon = 50.04%

Hydrogen = 5.59%

Oxygen = 44.37%

Divide by their molar mass

C = 50.04 / 12 = 4.17

H = 5.59 / 1 = 5.59

O = 44.37 / 16 = 2.773

Divide by the smallest

C = 4.17 / 2.773 = 1.5

H = 5.59 / 2.773 = 2

O = 2.773 / 2.773 = 1

Multiply by 2 to express in whole number

C = 1.5 × 2 = 3

H = 2 × 2 = 4

O = 1 × 2 = 2

Therefore, the empirical formula of the compound is C₃H₄O₂

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A 72 kg object moving 25 m/s will require the greatest amount of force

Given

mass of object and the velocity

Required

the greatest amount of force

Solution

Newton's 2nd law :

∑F = m. a  

F = force, N  

m = mass = kg  

a = acceleration due to gravity, m / s²  

Assuming the object is moving from rest (vo = 0) and the time needed to reach its velocity is the same (delta t = equal), it can be formulated:

[tex]\tt \Sum F=m.\dfrac{v_f-v_i}{\Delta t}\\\\F=m.\dfrac{v_f}{\Delta t}[/tex]

So the force on an object depends on the product of its mass and velocity

Or if we use the impulse and momentum formula

[tex]\tt F.\Delta t=m(v_f-v_i)\\\\F,\approx m.v_f[/tex]

So that we determine which is the greatest from the multiplication of mass and velocity will produce the greatest force as well

A 72 x 25 = 1800

B. 55 x 32 =1760

C. 75 x 22 = 1650

D.63 x 27 = 1701

Option A has the greatest force

form the molar concentration of the Ca(OH)2 which is a base we can deduct the pOH

pOH=-lg[OH-]

[OH-]=8.8 x 10-4 M

pOH=4

pH=14-pOH

pH=10

-lg[H+]=10

[H+]=10^-10

The concentration of Hydrogen ion [H⁺] in 8.8×10¯⁴ M Ca(OH)₂ is 5.68×10¯¹² M

The concentration of Hydrogen ion [H⁺] in a solution talks about the acidicity  the solution. Thus, we can obtain the concentration of Hydrogen ion [H⁺] in 8.8×10¯⁴ M Ca(OH)₂ solution as illustrated below:

Data obtained from the question

Concentration of Ca(OH)₂ = 8.8×10¯⁴ M  

Concentration of Hydrogen ion [H⁺] =..?  

Determination of the concentration of Hydroxide ion [OH¯]

 Concentration of Ca(OH)₂ = 8.8×10¯⁴ M

Concentration of Hydroxide ion [OH¯] =?  

Ca(OH)₂ (aq)⇄Ca²⁺ (aq) + 2OH¯(aq)  

From the balanced equation above,  

1 mole Ca(OH)₂ produced 2 moles of OH¯.

Therefore, 8.8×10¯⁴ M Ca(OH)₂ will produce = 8.8×10¯⁴ × 2 = 1.76×10¯³ M

Thus, the Concentration of Hydroxide ion [OH¯] is 1.76×10¯³ M  

Determination of concentration of Hydrogen ion [H⁺].  Concentration of Hydroxide ion [OH¯] = 1.76×10¯³ M

[tex]H^{+} * OH^{-} = 1*10^{-14}\\H^{+} * 1.76^{-3} = 1*10^{-14}[/tex]

Divide both side by 1.76×10¯³  

[tex]H^{+} = \frac{1*10^{-14} }{1.76*10^{-3}}\\[/tex]

[H⁺] = 5.68×10¯¹² M  

Therefore, the concentration of Hydrogen ion [H⁺] in the solution is 5.68×10¯¹² M  

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Answer:

Petals are modified leaves that surround the reproductive parts of flowers. They are often brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called corolla.

Answer:

Detail is given below

Explanation:

Differences:

Ionization involves the formation of ions while in dissociation substance are break into atoms, ions or molecules.

In ionization atoms and molecules gain positive or negative charge.

While in dissociation positive and negative ions are not essentially formed substance could be break into neutral small particles.

Ionization occur in covalent compounds while dissociation occur in ionic compound.

Ionization example:

Cl + e⁻    →  Cl⁻

Dissociation example:

NaCl   →   Na⁺ + Cl⁻

Here sodium and chloride ions are formed but in sodium chloride these ions were already present.

Another example:

N₂O₄   →     2NO₂

Answer:

Mass = 713.4 ×10⁻⁴ g

Explanation:

Given data:

Number of moles of calcium phosphate = 2.3×10⁻⁴ mol

Mass of calcium phosphate = ?

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of calcium phosphate is 310.18 g/mol

by putting values,

2.3×10⁻⁴ mol = mass / 310.18 g/mol

Mass = 2.3×10⁻⁴ mol × 310.18 g/mol

Mass = 713.4 ×10⁻⁴ g

Answer:

D. Halogens

Explanation:

All elements in these groups have 7 valence electrons, meaning their electronegativity is the highest among the elements.

Answer:

The sugar atoms formed new atoms after caramelization.

Explanation:

When sugar is heated to a certain temperature, it becomes caramel. Te formation of caramel from the sugar is a chemical process.

In the context, Pedro is doing an investigation by heating sugar to make caramel. Burning of the sugar crystal is a chemical change as different chemicals are present in both. The caramel formed cannot be revered back to sugar crystal, this also proves the chemical change of caramelization of sugar cubes. Sugar consists of carbon, oxygen and hydrogen atoms. It reacts with atmospheric oxygen atoms to form new groups of atoms and forms caramel.

Answer:

Kinetic Energy (Hope This Helps)

Explanation:

(Brainliest)

Answer:

Chemical energy to kinetic energy. (Arguably heat energy (thermal) because of respiration)

Answer:

C

Explanation:

A. analyzing results

B. collecting data

C. choosing controlled variables

D. making a prediction

The correct answer would be choosing controlled variables.

The controlled variables are factors that are kept constant among the different groups of subjects during the course of an experiment so as to be able to isolate the effects of a single factor - the independent variable.

There are basically 3 types of variables in a scientific experiment;

1. The independent variable

2. The dependent variable

3. The controlled variable

The independent variables are the variables whose effects are to be determined in the course of experiments. The dependent variables are the variables that are actually measured during the course of experiments and whose values vary along with that of the independent variables. The controlled variables are other variables required for the experiment but which must be kept constant among subjects in order to be able to isolate the effects of the independent variable.

The correct option is C.

Answer:

Cu2+

Srry if I didnt help..

The metallic ion in the compound CuCl₂ is copper (Cu).

CuCl₂ is a combination of copper (Cu) and chlorine (Cl) ions. In this compound, copper has a positive charge of 2, and chlorine has a negative charge of 1. Copper is a type of metal that can make different charged particles (called ions) depending on what it combines with and how it reacts.

In CuCl₂, the copper ion has a positive charge of 2. This means that it has given away two electrons and has an oxidation state of +2. The chlorine ions have a negative charge of -1 because they have taken in one electron. This shows that they have an oxidation state of -1.

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Answer:

my best guess is b

Explanation:

typically the lower the pitch the longer the wave line inbetween the inclines are

Answer:

310.53 g of Cu.

Explanation:

The balanced equation for the reaction is given below:

CuSO₄ + Zn —> ZnSO₄ + Cu

Next, we shall determine the mass of CuSO₄ that reacted and the mass Cu produced from the balanced equation. This can be obtained as follow:

Molar mass of CuSO₄ = 63.5 + 32 + (16×4)

= 63.5 + 32 + 64

= 159.5 g/mol

Mass of CuSO₄ from the balanced equation = 1 × 159.5 = 159.5 g

Molar mass of Cu = 63.5 g/mol

Mass of Cu from the balanced equation = 1 × 63.5 = 63.5 g

Summary:

From the balanced equation above,

159.5 g of CuSO₄ reacted to produce 63.5 g of Cu.

Finally, we shall determine the mass of Cu produced by the reaction of 780 g of CuSO₄. This can be obtained as follow:

From the balanced equation above,

159.5 g of CuSO₄ reacted to produce 63.5 g of Cu.

Therefore, 780 g of CuSO₄ will react to produce = (780 × 63.5)/159.5 = 310.53 g of Cu.

Thus, 310.53 g of Cu were obtained from the reaction.

Answer:

Kr-73 = 23.625 sec

Kr-74 = 10.0625 minutes (603.75 seconds)

Kr-76 = 12.95 hours (777 minutes)

Kr-81 = 1.8375 * 10^6 years

Explanation:

What you do is multiply each of those amounts by 7/8.

27 * 7/8 = 189/8 = 23.625

23/2 * 7/8 = 161/16 = 10.0625

74/5 * 7/8 = 518/40 = 259/20 = 12.95

210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6

Mass of copper : 0.165 g

Given

5.0 A over 100 seconds

Required

Mass of copper

Solution

Faraday's law:

The mass of the substance formed at each electrode is proportional to the electric current flowing in the electrolysis

[tex]\tt W=\dfrac{e.i.t}{96500}[/tex]

e = Ar / valence = eqivalent weight

i = current

t = time

W = weight

CuSO₄ ----> Cu²⁺ + SO₄²⁻

Cu ----> Cu²⁺ + 2e

e = Ar/2

= 63,5/2 = 31,75

[tex]\tt W=\dfrac{31.75\times 5\times 100}{96500}=0.165~g[/tex]

Answer:

Explanation:

A. conducts electricity in both solid and liquid state.

   Metal

B. conducts electricity in solid state but its electrical conductivity in liquid state is unknown. Also it burns at a vey high temperature to give off carbon dioxide gas.

   Graphite

C. conducts electricity in liquid state but not in solid state

    Ionic compound

D. does not conduct electricity in any state

    Covalent compound

A metal is a substance that conducts both heat and electricity in solid and liquid state. They do this by the presence of free mobile electrons within their atomic space.

Graphite is a non - metal but it has free mobile electrons within its carbon frame work that allows of electrical conduction.

Ionic compounds are conductors only in molten state. In solid state, they do not conduct electricity and are called electrolytes in their liquid or molten form.

Covalent compounds do not ionize in solution and will not have ions which can conduct electric current.

Ranks the objects from most to least dense : X,Z,Y,W

Given

Object W : m=16 g, V=84 cm³

Object X : m=12 g, V= 5 cm³

Object Y : m=4 g, V= 6 cm³

Object Z : m=408 g g, V= 216 cm³

Required

Density

Solution

Density formula:  

[tex]\large {\boxed {\bold {\rho ~ = ~ \frac {m} {V}}}}[/tex]

ρ = density  

m = mass  

v = volume  

1. Object W

[tex]\tt \rho=\dfrac{16}{84}=0.19[/tex]

2. Object X

[tex]\tt \rho=\dfrac{12}{5}=2.4[/tex]

3. Object Y

[tex]\tt \rho=\dfrac{4}{6}=0.67[/tex]

4. Object Z

[tex]\tt \rho=\dfrac{408}{216}=1.89[/tex]

From most to least dense : X,Z,Y,W

Answer:

the equation could have mulitplication and square roots which may change the function of the line

Answer:

+4

Explanation:

Answer:

Speed is how fast you cover a certain distance

[tex]Speed=\frac{Distance}{time}[/tex]

Answer:

Yes

Explanation:

Answer:the plural of walrus is walruses

Explanation:

Answer:

C) number of occupied energy shells

Explanation:

Atomic numbers of different elements must differ, as well as atomic masses. The number of oxidation states differs per atom as well.

Answer:

19.11g

Explanation:

mole = mass ÷ molar mass

mole = 2.61 ÷ 27

mole = 0.097mol

Number of atoms in 2.61g of Aluminum = 6.022 × 10^23 × 0.097

= 0.584 × 10^23

= 5.84 × 10^22atoms

To get the same number of atoms for Gold (Au), we multiply the atomic mass of Au by 0.097mol

Atomic mass of Au = 197g/mol

mass = mole × molar mass

mass = 0.097 × 197

mass = 19.109g

mass = 19.11g

A scoop of potassium oxide was placed in 55g of water which produced 67g of potassium hydroxide then mass of potassium oxide was used is 12g

Potassium oxide is used widely in the agricultural industry as a fertilizer

Here given data is

Potassium oxide was placed in 55g of water which produced 67g of potassium hydroxide

We have to calculate mass of potassium oxide was used =?

Then the reaction is

K₂O + H₂O → KOH

x + 55g = 67g

x = 67g - 55g

x = 12g

Therefore mass of potassium oxide was used is 12g

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Answer:

I dont see anything.

Explanation:

But an element is a substance that is made only out of one atom.

Answer:

you must go to jones im doing the same test

Explanation:

Answer:

The answer is C

Explanation:

Thomson conducted many tests with cathode rays. Which led to his discovery of the electron.