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Scientists use different types of microscopes to observe objects that are not visible to the naked eye. A scientist is
reviewing various samples of pond water to determine what species of microorganisms live in the pond. The scientist
wishes to make drawings of the structure of each microorganism and study each one's method of movement. Which of
the following microscopes would be best for the scientist to use?
transmission electron microscope
b. scanning electron microscope
c. compound light microscope
d. dissecting microscope
a.
Please select the best answer from the choices provided
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Sono

Answer:

The most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Explanation:

The mass, in percentage, of eah isotope of Calcium is their fractional composition multiplied by 100:

40Ca-0.96941*100 =  96.941% of ⁴⁰Ca

42Ca-0.00647*100 = 0.647% of ⁴²Ca

43Ca-0.0013*100 = 0.13% of ⁴³Ca

44Ca-0.02086*100 = 2.086% ⁴⁴Ca

46Ca-0.00004*100 = 0.004% ⁴⁶Ca

48Ca-0.00187*100 = 0.187% of ⁴⁸Ca

That means the most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Answer:

I dont no ma men

Explanation:

Sorry cause a dont no

Answer:

Work is a force causing the movement or displacement of an object

law of conservation mass:

1. Atoms cannot be created or destroyed in a chemical reaction.

2. Molecules cannot be created or destroyed in a chemical reaction.

3. Compounds cannot be created or destroyed in a chemical reaction.

4. Heat cannot be created or destroyed in a chemical reaction.

Answer:

Yes.

Explanation:

Yes, enough folic acid in the body by the early weeks of pregnancy helps to prevent spina bifida. The body of woman uses folate during the pregnancy which produces red and white blood cells that help your baby to grow. Folate also lowers the risk of neural tube defect (NTD) in the unborn baby. Neural tube defect (NTDs) are the serious birth defects that greatly affect the spinal cord, brain and skull of the baby.

Answer:

Hi, there the answer is D.

Explanation:

Answer:

Your welcome! :)

Explanation:

THE PROCESS IS: Radioactive decay involves the emission of a particle and/or energy as one atom changes into another. In most instances, the atom changes its identity to become a new element.

THE DEFINITION IS: Decay, decompose, rot, putrefy, spoil mean to undergo destructive dissolution. decay implies a slow change from a state of soundness or perfection. a decaying mansion decompose stresses a breaking down by chemical change and when applied to organic matter a corruption.

The question is incomplete, the complete question is:

A certain substance X has a normal freezing point of [tex]-6.4^oC[/tex] and a molal freezing point depression constant [tex]K_f= 3.96^oC.kg/mol[/tex]. A solution is prepared by dissolving some glycine in 950. g of X. This solution freezes at [tex]-13.6^oC[/tex]. Calculate the mass of urea that was dissolved. Round your answer to 2 significant digits.

Answer: 129.66 g of glycine will be dissolved.

Explanation:

Depression in the freezing point is the difference between the freezing point of the pure solvent and the freezing point of the solution.

The expression for the calculation of depression in freezing point is:

[tex]\text{Freezing point of pure solvent}-\text{freezing point of solution}=i\times K_f\times m[/tex]

                                 OR

[tex]\text{Freezing point of pure solvent}-\text{freezing point of solution}=i\times K_f\times \frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent (g)}}[/tex]        ....(1)

where,

i = Van't Hoff factor = 1 (for non-electrolytes)

Freezing point of pure solvent = [tex]-6.4^oC[/tex]

Freezing point of solution = [tex]-13.6^oC[/tex]

[tex]K_f[/tex] = freezing point depression constant  = [tex]3.96^oC/m[/tex]

[tex]M_{solute}[/tex] = Molar mass of solute (glycine) = 75.07 g/mol

[tex]w_{solvent}[/tex] = Mass of solvent = 950 g

Plugging values in equation 1:

[tex]-6.4-(-13.6)=1\times 3.96\times \frac{\text{Given mass of glycine}\times 1000}{75.07\times 950}\\\\\text{Given mass of glycine}=\frac{7.2\times 75.07\times 950}{1\times 3.96\times 1000}\\\\\text{Given mass of glycine}=129.66g[/tex]

Hence, 129.66 g of glycine will be dissolved.

Answer:

a

Explanation:because i did the test

Various structures, or allotropes, of carbon, are precious stone, graphite, and fullerenes. In jewel, every carbon iota is attached to four other carbon iotas, shaping an unbending construction that makes precious stones hard.

Answer:

7.4

Explanation:

Plasma proteins are part of the buffer systems of blood plasma. Plasma contains both positively and negatively charged amino and carboxyl groups. These compounds' charged portions can attract and link hydrogen(H) and hydroxyl ions(OH-), therefore act as buffers.

Plasma serves as a weak and ineffective buffer. The pH of a buffer should always be around 7.4 which is nearly neutral. As such we may deduce from the first experimental observation that there is no change in pH.

How does glue, borax, and water turn into slime, scientifically?

Answer:

Q:Use the Hertzsprung-Russell diagram and temperature and luminosity data to identify each star

Explanation:

Take it as u please

Answer:

white dwarf- star C

main sequence- star A

giant- Star B

Explanation:

Got it right

Caustic soda, NaOH, can be prepared commercially by the reaction of Na2CO3 with slaked lime, Ca(OH)2. 1.509 kg of NaOH can be obtained by treating 1.350 kg of Na2CO3 with Ca(OH)2.

Caustic soda means an alkali salt or  Lye, which is the common name of sodium hydroxide due corrosive nature of this salt on animal and plant tissues.

It is used in a wide range of applications and the chemical formula of sodium hydroxide is NaOH, used as cleansing agent and also in manufacturing of washing soda.

sodium hydroxide cam also applied as the reagent in the laboratories, preparation of soda lime, used in extraction of aluminum by purifying bauxite.

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Answer: The volume of given amount of ethanol at this temperature is 159.44 mL

Explanation:

Specific gravity is given by the formula:

[tex]\text{Specific gravity}=\frac{\text{Density of a substance}}{\text{Density of water}}[/tex]

We are given:

Density of water = 0.997 g/mL

Specific gravity of ethanol = 0.787

Putting values in above equation, we get:

[tex]0.787=\frac{\text{Density of a substance}}{0.997g/mL}\\\\\text{Density of a substance}=(0.787\times 0.997g/mL)=0.784g/mL[/tex]

Density is defined as the ratio of mass and volume of a substance.

[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)

Given values:

Mass of ethanol = 125 g

Density of ethanol = 0.784 g/mL

Putting values in equation 1, we get:

[tex]\text{Volume of ethanol}=\frac{125g}{0.784g/mL}=159.44mL[/tex]

Hence, the volume of given amount of ethanol at this temperature is 159.44 mL

Answer:

oxygen is add to ATP providing energy to the cell

Answer:

A).

Strontium Sulphate is soluble

Answer:

21g

Explanation:

no.ofmol fe2o3=39.5/(56×2+16×3)=0.25mol

from equation 1mole fe2o3 react with 3mole co

so,0.25mol fe2o3 react with 0.75mol co

mass of co=0.75×(12+16)=21g

Answer:

Approximately [tex]20.8\; \rm g[/tex].

Explanation:

[tex]\rm Fe_2O_3 \, (s) + 3\; CO\, (g) \to 2\; Fe\, (s) + 3\; CO_2\, (g)[/tex].

Relative atomic mass:

Formula mass:

[tex]\begin{aligned}M({\rm Fe_2O_3}) &= 2 \times 55.845 + 3 \times 15.999\\ &= 159.687\; \rm g \cdot mol^{-1}\end{aligned}[/tex].

[tex]\begin{aligned}M({\rm CO}) &= 12.011 + 15.999\\ &= 28.010\; \rm g \cdot mol^{-1}\end{aligned}[/tex].

Number of moles of [tex]\rm Fe_2O_3[/tex] formula units in [tex]39.5\; \rm g[/tex] of this compound:

[tex]\begin{aligned}&n({\rm Fe_2O_3}) \\ &= \frac{m({\rm Fe_2O_3})}{M({\rm Fe_2O_3})} \\ &= \frac{39.5\; \rm g}{159.687\; \rm g \cdot mol^{-1}}\approx 0.247\; \rm mol\end{aligned}[/tex].

Refer to the balanced equation for this reaction.

Hence, for every formula unit of [tex]\rm Fe_2O_3[/tex] that this reaction consumes, [tex]3\; \rm mol[/tex] of [tex]\rm CO[/tex] molecules would also need to be consumed. Therefore, if neither reactant is in excess:

[tex]\displaystyle \frac{n({\rm CO})}{n({\rm Fe_2O_3})} = \frac{3}{1} = 3[/tex].

Calculate the number of moles of [tex]\rm CO[/tex] required to react with that [tex]39.5\; \rm g[/tex] of [tex]\rm Fe_2O_3[/tex]:

[tex]\begin{aligned}&n({\rm CO}) \\ &= n({\rm Fe_2O_3}) \cdot \frac{n({\rm CO})}{n({\rm Fe_2O_3})} \\[0.5em] &\approx 0.247\; \rm mol \times 3 \approx 0.742\; \rm mol\end{aligned}[/tex].

Make use of the formula mass of [tex]\!\rm CO[/tex] to find the mass of that [tex]0.742\; \rm mol[/tex] of [tex]\rm CO[/tex] molecules:

[tex]\begin{aligned} m({\rm CO}) &= n({\rm CO}) \cdot M({\rm CO}) \\ &\approx 0.742\; \rm mol \times 28.010\; \rm g \cdot mol^{-1} \\ &\approx 20.8\; \rm g\end{aligned}[/tex].

Answer:

A parasitic relationship is one in which one organism, the parasite, lives off of another organism, the host, harming it and possibly causing death. The parasite lives on or in the body of the host.

Answer:56.98496

Explanation:

half if diameter is radius or 1.55 and double the radius is 3.10 or the length of the diameter. you have a height given, so use the radius and heaight to plug it in the circular cylinder calculator and you get 56.98496

Answer:

The required specific enthalpy for oxygen = 8277.34 J/mol

Explanation:

Given that :

Pressure = 2.4 atm

Temperature = 310 K

specific internal energy U = 5700 J/mol

To find the specific enthalpy using the formula:

H = U + PV

where;

H is known as the specific enthalpy

Recall that from ideal gas equation

PV = nRT

For specific enthalpy, it is constant that n = 1

Thus;

PV = RT

replacing that into the equation (H = U + PV), we have:

here;

R = 8.314 J/mol K (constant)

H = U + RT

H = 5700 J/mol +( 8.314 J/mol K × 310 K)

H = 5700 J/mol + ( 2577.34 J/mol)

H = 8277.34 J/mol

Answer:

43.2 mol C

115 mol H

158 mol of atoms

Explanation:

Step 1: Given data

Moles of C₃H₈: 14.4 mol

Step 2: Calculate the number of moles of C

The molar ratio of C₃H₈ to C is 1:3. The moles of C are 3/1 × 14.4 mol = 43.2 mol.

Step 3: Calculate the number of moles of H

The molar ratio of C₃H₈ to H is 1:(. The moles of H are 8/1 × 14.4 mol = 115 mol.

Step 4: Calculate the total number of moles of atoms

n = nC + nH = 43.2 mol + 115 mol = 158 mol

Answer:

C₁₅N₃H₅

Explanation:

Let's assume we have 240 g of the dye (1 mol), in that case we'd have:

Now we convert the masses of each element into moles, using their respective molar masses:

Thus the molecular formula is C₁₅N₃H₅.

Answer:

2.6

Explanation:

Step 1: Given and required data

Step 2: Calculate the acid dissociation constant (Ka) of butanoic acid

We will use the following expression.

pKa = -log Ka

Ka = antilog - pKa

Ka = antilog -4.82 = 1.51 × 10⁻⁵

Step 3: Calculate [H⁺] of the solution

For a weak acid, we can use the following expression.

[H⁺] = √(Ca × Ka)

[H⁺] = √(0.35 × 1.51 × 10⁻⁵) = 2.3 × 10⁻³ M

Step 4: Calculate the pH of the solution

pH = -log [H⁺] = -log 2.3 × 10⁻³ = 2.6

Answer:

Rate = 0.83M/s

Explanation:

Rate of a chemical reaction is the 'absolute value' of change in concentration per unit time. That is ...

Rate = |Change in concentration / unit time|

= |Δ[Conc]/Δtime|

= |(1.17M -2.00M) / 25.3s|

= |- 0.83M/s|

= 0.83M/s*

------------

*Note: Some scholars define rate of reaction as a 'scaler' quantity having only magnitude as rate of reaction in a physical sense (up, down, right, left) is not definitive. In physical mechanics, rate is assigned a direction and magnitude of action and becomes a 'vector' quantity.

The speed at which the reaction occurs is called the rate of reaction. The rate of reaction for the decreased concentration is 0.83 M/s.

The reaction rate is the increase or decrease in the concentration of the products per unit of time. The formula for a reaction rate is given as,

[tex]\rm Rate = \rm \dfrac {\text{Change in concentration}} {Unit \; time}[/tex]

Given,

Initial concentration = 1.17 m

Final concentration = 2.00 M

Time = 25.3 sec

Substituting values in the above equation:

[tex]\begin{aligned} &= \dfrac{1.17 - 2.0} {25.3}\\\\&= -0.83\\\\&= 0.83 \;\rm M/s\end{aligned}[/tex]

Therefore, 0.83 M/s is the reaction rate.

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Answer:

SI

Explanation:

I would say silicon because it is also another metalloid. Boron is a metalloid.

Explanation:

Heterocyclic aromatic amine: The amine nitrogen is part of an aromatic ring. ... Use a number to locate the amino group on the parent chain. The IUPAC name of CH3CH2CH2CH2CH2NH2 is 1-pentylamine.

The name of the compound CH₃CH₂CH₂CH₂CH₂NH₂ is 1-pentylamine.

Organic compounds are named according to the set of rules provided by the international union of pure and applied chemistry (IUPAC). According to it,1) the chain of carbon atoms having highest number of carbon atoms is selected.

2)according to the number of carbon atoms in chain, parent chain is named.

3) Numbering is done in such a way that substituent if present the carbon on which it is present gets the lowest number.

4) The functional group which is present is mentioned as a suffix along with the carbon position on which it is present.

For example,CH₃CH₂CH₂CH₂CH₂NH₂ is named as follows :

1) As there is only one chain present, amine functional group being present it is numbered from the left hand side as the amine group will get the lowest number.

2) The name is given by writing the parent name that is pentane along with the position of amine group which is carbon-1.

Thus, it is named as 1-pentylamine.

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Answer: As temperature increases, the number of collisions increases and the energy of the collisions increases.

Explanation:

According to collision theory, for a reaction to take place it is necessary to have collisions between the reacting species or atoms.

A collision will only be effective if species coming together have a certain minimum value of internal energy equal to the activation energy of the reaction.

More is the number of collisions taking place in a chemical reaction more will be the kinetic energy of its molecules. As kinetic energy is the energy acquired due to motion of atoms or a substance.

Also, collisions increases with increase in temperature as:

[tex]K.E = \frac{3}{2}kT[/tex]

Kinetic energy is directly proportional to temperature. So, more is the temperature more will be energy of molecules.

Thus, we can conclude that as temperature increases, the number of collisions increases and the energy of the collisions increases.

Answer:

obviously 2 is the answer