Which of these can be found in a plant cell, but not in an animal cell?

Answer:

sodium

Explanation:

sodium is the second most reactive. Magnesium being the least reactive

Answer:

cesium

Elements with the Highest Reactivity

Francium is radioactive, with no stable isotopes. The most chemically reactive metal with a stable isotope is cesium. Cesium reacts explosively with water

Explanation:

Answer:

1.593 moles

Explanation:

Therefore, 1.593 moles are equal to 89.23 g of calcium oxide.

Answer:

9.64 × 10²³ molecules

Explanation:

Given data:

Mass of calcium oxide = 89.23 g

Number of molecules = ?

Solution:

First of all we will calculate the number of moles of calcium oxide.

Number of moles = mass/molar mass

Number of moles = 89.23 g/ 56.1 g/mol

Number of moles = 1.6 mol

Number of molecules;

1 mole contain 6.022 × 10²³ molecules

1.6 mol × 6.022 × 10²³ molecules / 1mol

9.64 × 10²³ molecules

The number 6.022 × 10²³ is called Avogadro number.

Answer:

a. True.

Explanation:

Hello!

In this case, since dullness and smoothness are characteristic of materials that are not able to conduct the electricity, as they do not provide an appropriate pathway for the electrons to move around because of their amorphous structure, we realize the answer is a. True.

On the contrary, a lustrous and robust solid, is actually able to conduct electricity because it provides the pathway for the electron movements and therefore to conduct electricity.

Best regards!

Answer:

3 half-lives 7. An isotope of Cesium (Cesium-137) has a half life of 30 years. If 1.0 mg of cesium-137 disintegrates over a period of 90 years, how many mg of cesium-137 would remain? of sodium-25 is 60 seconds? : 3 minutes t=601 = 3 half-lives 5.0mg ~ 2.5 mg + 1.25mg →) 625 mg.

Explanation:

Hope this helps

       where:

      [tex]N_{0}[/tex] = Initial quantity of the sample = 1.0g

       t = time in years of disintegration = 90 years

      [tex]t\frac{1}{2}[/tex] = Half life of cesium isotope = 30 years

      N(t) = Quantity of substance after disintegration = ?

N(t) =  [tex]1 ( \frac{1}{2})^ \frac{90}{30}[/tex]

N(t) =  [tex]1 (\frac{1}{2})^{3}[/tex]

N(t) = 0.125 grams

Therefore, the quantity of cesium-137 that would remain after disintegrating over a period of 90 years is 0.125 grams.

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Answer:

[tex]0.1090\ \text{M}[/tex]

Explanation:

Volume of [tex]KOH[/tex] = 41.22 mL

Molarity of [tex]KOH[/tex] = 0.1322 M

Number of moles of [tex]KOH[/tex]

[tex]n=\text{Molarity}\times \text{Volume of }KOH\\\Rightarrow n=0.1322\times 41.22\times 10^{-3}\\\Rightarrow n=0.005449284\ \text{mol}[/tex]

2 moles of [tex]KOH[/tex] reacts with 1 mole of [tex]H_2SO_4[/tex]

So,

[tex]0.005449284\ \text{mol}[/tex] of [tex]KOH[/tex] reacts with M mole of [tex]H_2SO_4[/tex]

[tex]M=\dfrac{0.005449284}{2}=0.002724642\ \text{mol}[/tex]

Volume of [tex]H_2SO_4=25\times 10^{-3}\ \text{L}[/tex]

Concentration of [tex]H_2SO_4[/tex] is

[tex]M=\dfrac{0.002724642}{25\times 10^{-3}}\\\Rightarrow M=0.10898568\approx 0.1090\ \text{M}[/tex]

The concentration of the unknown [tex]H_2SO_4[/tex] solution is [tex]0.1090\ \text{M}[/tex].

Answer:

52.8 Liters

Explanation:

Gay-Lussacs law states that P1/T1 = P2/T2

if:

then:

45/298.1 = P2/328.1

P2 = 52.8

The new volume of the balloon is 52.8 Liters this can be calculated by using gas laws.

Charles law states the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature. It is given by

V₁/T₁ = V₂/T₂

What information do we have?

V₁ = 45 L

T₁ = 25 + 273.1 =298.1 K

T₂ = 55 + 273.1 = 328.1 K

To find:

V₂= ?

On substituting the values:

45/298.1 = V₂/328.1

V₂ = 52.8 L

Thus, the volume of the balloon is 52.8 liters.

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Answer:

The numerical value of K for the reaction is 2.36*10⁻⁴

Explanation:

A chemical equilibrium is a reaction that is never completed, since it occurs simultaneously in both directions (the reactants form products, and in turn, these form reactants again). In other words, it is a dynamic balance. When the concentrations of each of the substances involved (reactants or products) stabilize, that is, they are spent at the same rate as they are formed, chemical equilibrium is reached.

The equilibrium constant (Kc) is expressed as the ratio between the molar concentrations of reactants and products. Its value in a chemical reaction depends on the temperature, so this must always be specified.

Being:

aA + bB ⇄ cC + dD

then the constant Kc is:

[tex]Kc=\frac{[C]^{c} *[D]^{d} }{[A]^{a} *[B]^{b} }[/tex]

In the case of the reaction:

A₂(g) + 3 B₂(g) ⇒ 2 AB₃(g)

The constant Kc is:

[tex]Kc=\frac{[AB_{3} ]^{2} }{[A_{2} ] *[B_{2} ]^{3} }[/tex]

Being:

and replacing, you get:

[tex]Kc=\frac{(7.6*10^{-4} )^{2} }{0.0055 *(0.763)^{3} }[/tex]

Kc=2.36*10⁻⁴

The numerical value of K for the reaction is 2.36*10⁻⁴

Answer:

Heat energy can be calculated by using the specific heat of a substance multiplying it to the mass of the sample and the

change in temperature. It is expressed as:

Energy = mCAT

Energy = 100 (0.90) (150 - 30)

Energy = 10800 J

Answer:

If the volume of a gas increased from 2 to 6 L while the temperature was held constant, the  pressure of the gas decreased by a factor of 3.

Explanation:

Boyle's law that says "The volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure." This means that if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases.

Boyle's law is expressed mathematically as:

Pressure * Volume = constant

or

P * V = k

To obtain the proportionality factor k you must make the quotient:

[tex]k=\frac{V2}{V1} =\frac{6 L}{2 L}[/tex]

k= 3

This means that if the volume of a gas increased from 2 to 6 L while the temperature was held constant, the  pressure of the gas decreased by a factor of 3.

Answer:

Na sodium or Rb rubidium

Explanation:

Because Na is present in first group all members of group 1 have 1 electron in valence shell and show similar properties.

Answer:

B: CaCO3 + 2HCl -> CaCl2 + H2CO3

Explanation:

Count how many elements they are in all molecules for the reactants and for the products.

Ca = 1 element

C = 1 element

O = 3 elements

H = 1 element

Cl = 1 element

Ca = 1 element

Cl = 2 elements

H = 2 elements

C = 1 element

O = 3 elements

To balance this equation, we need to add 1 more element of Chlorine and Hydrogen.  Therefore, we add a 2 to the coefficient of HCl for the reactants side.

Now let us try it.

Count how many elements they are in all molecules for the reactants and products.

Ca = 1 element

C = 1 element

O = 3 elements

H = 2 element

Cl = 2 element

Ca = 1 element

Cl = 2 elements

H = 2 elements

C = 1 element

O = 3 elements

All of the elements are balanced.

Hope it helped!

Answer:

a = 2m/s²

Explanation:

Given data:

Mass of sofa = 150 Kg

Force applied = 300 N

Acceleration = ?

Solution:

Formula:

F = ma

F = force

m = mass

a = acceleration

by putting values,

300 N = 150 Kg × a

a =  300 N /150 Kg

a = 300 Kg m/s² / 150 Kg   ( N = Kgm/s²)

a = 2m/s²

Answer:

NaOH + HCl —> NaCl + H₂O

Explanation:

From the question given above, we obtained the following equation:

4NaOH + 4HCl —> NaCl + H₂O

The equation can be balance as follow:

4NaOH + 4HCl —> NaCl + H₂O

There are 4 atoms of Na on the left side and 1 atom on the right side. It can be balance by putting 4 in front of NaCl as shown below:

4NaOH + 4HCl —> 4NaCl + H₂O

There are a total of 8 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 4 in front of H₂O as shown below:

4NaOH + 4HCl —> 4NaCl + 4H₂O

Next, divide through by 4 to express the equation with the lowest coefficients.

NaOH + HCl —> NaCl + H₂O

Now the equation is balanced.

NOTE: Smallest coefficients are always used to represent a balanced equation.

Answer:

Definitely harder, since volleyballs are nowhere near as heavy as bowling balls, it’ll be harder too since there wont be much force to knock over pins

[tex]\purple{\tt{\huge{Answer}}}[/tex]

CH3COOH is an accepted and common form of writing the structure of acetic acid (commonly known as vinegar when diluted in water).

Answer: the answer is c

Explanation:

I just did the test

Each graph below represents a different type of electromagnetic wave. Then graph C most likely illustrates radio waves.

The electromagnetic field's waves, which travel through space and convey electromagnetic radiant energy, are what make up electromagnetic radiation. It consists of X-rays, gamma rays, microwaves, infrared, light, and radio waves. These waves are all a component of the electromagnetic spectrum.

There are seven different kinds of them are X-rays, gamma rays, visible light, infrared light, radio waves, and microwaves. They may be compared to seven distinct types of light.

Lower frequency electromagnetic radiation than microwaves is referred to be a radio wave. Radio waves have wavelengths that range from tens of thousands of meters to 30 centimeters. These are equivalent to frequencies between 3 Hz and 1 GHz (109 Hz).

Thus, option C is correct.

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Answer:

There are several ways of expressing the concentration of a solution.

Explanation:

Concentration is the proportion of a substance in a mixture. There are several ways of expressing them, each with their own usefulness. What's incredibly useful is with a little math and conversion factors, these can all be interconverted.

Note: to find the percent of some of these, such as for mass percent or volume percent, multiply the result by 100.

Additionally, with some practice you can answer a question such as, "The label on a 0.750-L bottle of Italian chianti says "11.5% alcohol by volume." How many liters of alcohol does the wine contain?". etc...

I really hope this helps! Take care.

Answer:

B. Thicker layer of blubber

Explanation:

For the leopard seals to survives this harsh environment, it must have a thicker layer of blubber

Blubber is a thick layer of fat. It is called the adipose tissues and found in most marine organisms.

Answer:

B

Explanation:

Answer:

A: CH4 + 2O2 -> CO2 + 2H2O

Explanation:

Count how many elements they are in all molecules for the reactants and for the products.

C = 1 element

H = 4 elements

O = 2 elements

C = 1 element

O = 2 elements

H = 2 elements

O = 1 element

2 oxygen atoms + 1 oxygen atoms = 3 oxygen atoms total on the products side.

To balance this equation, we need to add 2 more elements of hydrogen and 2 more elements of oxygen. Therefore, we add a 2 to the coefficient of O2 for the reactants side and add a 2 to the coefficient of H2O for the products side.

Now let us try it.

Count how many elements they are in all molecules for the reactants and products.

C = 1 element

H = 4 elements

O = 4 elements

C = 1 element

O = 2 elements

H = 4 elements

O = 2 elements

2 oxygen atoms + 2 oxygen atoms = 4 oxygen atoms total on the products.

All of the elements are balanced.

Hope it helped!

Explanation:

In a chemical reaction, the atoms and molecules produced by the reaction are called products.

In a chemical reaction, only the atoms present in the reactants can end up in the products. No new atoms are created, and no atoms are destroyed.

In a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.

Answer:

1 and 2

Trigonal planar

Tetrahedral

Trigonal Planar

Linear

Bent ( v- shape)

Explanation:

The highlighted atoms has a delocalized lone pair - 1 and 2

All sp2-hybridized carbon atoms have geometry- Trigonal planar

All sp3-hybridized carbon atoms have geometry - Tetrahedral

The nitrogen atom has geometry - Trigonal Planar

The oxygen atom of the C=O bond has geometry - Linear

and the other oxygen atom has geometry - Bent ( v- shape)

P.S - The correct question is -

Ramelteon has been an aromatic compound with 3 ring structure followed by the aliphatic chain.

The drug has antagonist structure to the melatonin and has been used to treat insomnia by acting as the melatonin representative.

The labelled atom in the structure is oxygen of the pentane ring, nitrogen in the aliphatic chain, and carbonyl oxygen.

The delocalized lone pair has been observed in the compound which has been contributing to the resonating structure. The delocalized lone pair ion the given structure is oxygen of the pentane ring, and nitrogen in the aliphatic chain.

The geometry of the atom has been based on the hybridization and the lone pairs.

The geometry of [tex]\rm sp^2[/tex] hybridized carbon has been trigonal planar. The geometry of [tex]\rm sp^3[/tex] hybridized carbon atom has been tetrahedral. The nitrogen in the chain has trigonal planar geometry. The C=O oxygen has been comprising  linear geometry, while the oxygen has bent v shape.

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Answer:

A- 1-Bromopentane

>2-Bromopentane> 2-Bromo-2-methylbutane

B- 1-Bromo-3-methylbutane>2-Bromo-3-methylbutane> 2-Bromo-2-methylbutane

C- 1-Bromobutane > 1-Bromo-3-methylbutane>1-Bromo-2-methylbutane>1-Bromo-2,2-dimethylpropane

Explanation:

We must bear in mind that the ease of SN2 reaction is methyl > primary> secondary> tertiary.

As a result of this all primary alky halides react faster towards SN2 than secondary and tertiary alkyl halides.

Also, compounds that may form more stable carbocations by 1,2- alkyl shifts are less likely to participate in SN2 reaction

Answer:

Photosynthesis transforms light energy into chemical energy by making sugars. Cellular respiration releases the chemical energy from food by breaking down sugars.

Explanation:

I'm actually learning this in school right now

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~PurpleMist

Answer:

Every mole contains 6.022 x 10^23 atoms regardless of what type of moelcules it is (Gold, Silver). So the anwer is 1.54 times 6.022 x 10^2

Answer:

It is a chemical change

Explanation:

The combination of sodium hydroxide and fat yields soap and glycerine.

We have to remember that one of the characteristics of a chemical change is that new substance(es) is/are formed. We have to look out for this when considering any process.

We can see here that new substances were formed (soap and glycerine). Based on this, we can assert that a chemical change has taken place.

Answer:

3.4027x10^-22

Explanation:

Answer:

D.

Explanation:

INCREASE OF SOLAR WINDS When the sun is more active