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3 years ago

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19) Which two structures are not found in animal cells? A) vacuoles and ribosomes B) chloroplasts and ribosomes C) cell walls an

d chloroplasts D) endoplasmic reticulum and cell walls

2 answers:

LUCKY_DIMON [66]3 years ago

7 0

The answer to your question is: C) Cell walls and chloroplasts

(I hope this helps!)

Molodets [167]3 years ago

5 0

Cell walls and Chloroplasts

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A well-insulated bucket of negligible heat capacity contains 129 g of ice at 0°C.

Luba_88 [7]

Answer:

The final equilibrium temperature of the system is $T = 12.48^oC$

For the ice it would melt completely the mass that would remain is Zero

Explanation:

In the following question we are provided with

Mass of the ice $M_{i}$ = 129 g = 0.129 kg

Mass of the steam $M_s$ = 19 g = 0.019 kg

Initial temperature is $T_i$ = 0°C

Temperature of steam $T_s$ = 100°C

Following the change of state of water in the question

The energy required by ice to change to water is mathematically given as

$Q_A = M_iL_f$

Where $L_f$ is a constant known as heat of fusion and the value is $334*10^3 J/kg$

$Q_A = 0.129 *334 *10^3 = 43086 J$

The energy been released when the steam changes to water is mathematically given as

$Q_B = M_s * L_v$

Where $L_v$ is a constant known as heat of vaporization and the value is $2256*10^3J/kg$

$Q_B = 0.019 * 2256*10^3 = 42864J$

The energy released when the temperature of water decrease from 100°C to 0°C is

$Q_C = M_s *C_water ($ 100°C)

Where $C_{water}$ is the specific heat of water which has a value $4186J/kg \cdot K$

$Q_C = 0.019 *4186*100 = 7953.4$

Looking at the values we obtained we noticed that ]

$Q_B + Q_C > Q_A$

What this means is that the ice will melt

bearing in mind the conservation of energy

looking the way at which water at different temperature were mixed according to the question

Heat lossed by the vapor = heat gained by ice

$Q_B + M_s *C_{water}(100-T) = Q_A + M_i C_{water} T$

$T = \frac{Q_B+M_s *C_{water}(100^oC)-Q_A}{(M_s *C_{water})+(M_i*C_{water})}$

$T = \frac{42864+7953.4-43086}{(0.019+0.129)(4186)}$

$T = 12.48^oC$

3 0

3 years ago

PLEASE HELP!!!!!!

Helga [31]

Hey there,

Density = Mass/Valume

D= 3.1/0.35

D= 8.86 g/cm3

3 0

4 years ago

Read 2 more answers

bonufazy [111]

If the gymnast mass were doubled, her height (h) from the top of the board would be as follows,

с Stay the same

Explanation:

The Mass of an object or body does not affect the acceleration due to gravity in any kind of way.
Light weight objects accelerate more slowly than the heavy objects because when the forces other than the gravity also plays a major role.
Mass increases of a body when an object has higher velocity or the speed.
The greater the force of gravity, it would give a direct impact on the object's acceleration; thus considering only a force, the heavier the object is, it would accelerate faster. But an acceleration depends upon the two factors which are force and mass.
Newton's second law of motion states that the acceleration of an object is dependent upon the two factors which are, the net force of an object and the mass of the object.

3 0

3 years ago

Identify the three types of isometric transformations. A. reflection, rotation, translation B. reflection, rotation, dilation C.

inessss [21]

<span>reflection, rotation, translation</span>

4 0

3 years ago

Why do atoms like carbon and nitrogen not like to make ions, while sodium and chlorine do?

KATRIN_1 [288]

The chemical behavior of atoms is best understood in terms of the degree to which an atom of a particular element attracts electrons, a characteristic officially known as electronegativity. When electronegativity is either very high (as in a chlorine atom) or very low (as in a sodium atom) then you have an atom which tends to either acquire or get rid of one or more electrons, and when it does so it becomes an ion. Carbon has a moderate electronegativity and therefore it is more likely to share electrons (forming covalent bonds) rather than either giving them up or acquiring them (forming ionic bonds). Nitrogen does have a relatively high electronegativity and does form ionic bonds, but in ionic compounds it is most often found in the nitrate radical, combined with 3 oxygen atoms. Nitrogen is also found in molecules that have covalent bonds, such as proteins, but it is the moderating influence of carbon that makes this happen.

I should add that inert elements such as helium do not attract electrons but neither do they give up the ones that they have; they are in a special category, and they form no bonds, neither ionic nor covalent.

6 0

3 years ago