SOMEONE HELP ME PLEASE ILL GIVE BRAINLY

Answer:

Dermal tissue of the stems and leaves is covered by a waxy cuticle that prevents evaporative water loss. Stomata are specialized pores that allow gas exchange through holes in the cuticle. Unlike the stem and leaves, the root epidermis is not covered by a waxy cuticle which would prevent absorption of water.

Explanation:

There are 2 lone pairs

Given

a molecule of calcium sulfide

two valence electron of Calcium(Ca)

six valence electrons of Sulfur(S)

Required

number of lone pairs of electrons

Solution

Lewis structure shows the form of bonds that occur in the valence electrons of an element or compound

Valence electrons are electrons used in a chemical bond

To achieve stability, the element S needs 2 more electrons which are obtained from 2 electrons from the Ca element,

A lone pair electrons means refers to an unshared pair of electrons(not bonding to the other atoms)

Answer:

It determines the number of molecules

Answer:

it means there are 3 hydrogen atoms in the compound.

Answer:

Dilute acid + carbonate used in making the salt of copper sulfate.

Explanation:

In this experiment an insoluble metal oxide is reacted with a dilute acid to form a soluble salt.Copper(II) oxide, a black solid, and colourless dilute sulfuric acid react to produce copper(II) sulfate,giving a characteristic blue colour to the solution.

Answer:

Pasteurization involves heating liquids at high temperatures for short amounts of time. Pasteurization kills harmful microbes in milk without affecting the taste or nutritional value (sterilization= all bacteria are destroyed).

Explanation:

Answer:

1. 95.7 ppm

2. 6.67 ppm

Explanation:

Podemos pensar la denominación ppm como partes por millón, es un tipo de unidad que define concentración de solutos en una solución.

ppm = μg/g  o si lo queremos ver en volumen, μg/mL

Quiere decir microgramos de soluto en 1 g de solución o mL de solución.

Ej 1.  En primer lugar convertimos los moles de KNO₃ a gramos

0.00071 mol . 101.1 g/mol = 0.071781 g

Si pasamos los gramos a μg → 0.071781 g . 1000000 μg/ 1g = 71781 μg

Dividimos 71781 μg /750 ml = 95.7 ppm

Ej 2. Convertimos los mg a μg → 4 mg . 1000 μg/ 1 mg = 4000 μg

Ahora dividimos: 4000 μg /600 ml = 6.67 ppm

Answer: C. The university surveys 600 randomly selected students who attend the university. Correct

Explanation:

22.72 is the average atomic weight of sodium.

Isotopes are different versions of a specific element.

1st isotopes of 22u = 28%

2nd isotopes of 23u = 72%

The average atomic weight of sodium be=

22 x 28 + 23 x72

=2272/100

=22.72

Hence, 22.72 is the average atomic weight of sodium.

Learn more about isotopes here:

https://brainly.com/question/13662697

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Answer:

C. There is a negative acceleration

Explanation:

I majored in Physics

Answer:

Metabolism

Explanation:

because energy change takes place

Answer:838J/kg/K

Explanation:

use : Q= mS◇ T

Answer:

35.50

Explanation:

There are two stable isotopes, 35Cl (75.77%) and 37Cl (24.23%), giving chlorine a standard atomic weight of 35.45

Answer:

0.04 M

Explanation:

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

Initial volume of solution (V1) = 25 cm³

Initial Molarity of solution (M1) = 0.4 M

Final volume of solution (V2) = 250 cm³

Final Molarity of solution (M2) =?

We can obtain the final Molarity of the solution by using the dilution formula as illustrated below:

M1V1 = M2V2

0.4 × 25 = M2 × 250

10 = M2 × 250

Divide both side by 250

M2 = 10/250

M2 = 0.04 M

Therefore, the resulting molarity of the diluted solution is 0.04 M

Answer:

Iron wood is very dense and will sink in water. B

Explanation:

Hope this helps!!

Answer:

B

Explanation:

Answer:

atmosphere, break up

Explanation:

Answer:

Atmosphere, break up

Explanation:

Answer:

Hg

Explanation: I just took the test

Answer:

2Al + 3Na2SO4 -----> Al2(SO4)3 + 6 Na

Explanation:

Product should be Al2(SO4)3

Because Al contains +3 charge

And SO4 contains -2 charge

To balance this postive and negative charge we multiple +3 with 2 and -2 with 3

Answer:

D?

Explanation:

I think D hmm is the answer if I am wrong pls anyone or someone type the right answer but for me is d

Answer:

NOT D!!!!

Explanation:

I am taking the quiz on ck12, it is NOT "none of the above"

Answer:

B. Respiration

Explanation:

cellular respiration is the process where cells use glucose (C6H12O6) and oxygen gas (O2) to make carbon dioxide (CO2) water (H2O) and ATP, which is energy

formula:

C6H12O6 + 6O2 -> 6CO2 + 6H20 + 38ATP  

Answer:

D

Explanation:

I'm doing USA test prep and I got it right

Answer:

Explanation:

It is D

Make the fan blades out of a lighter material.

Answer:

True

Explanation:

Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage.

For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water which bypasses the conversion to liquid stage and goes straight to the gaseous form.

Answer:

No.

Explanation:

This is because a solution is a mixture with two substances that have already dissolved in each other and so there is no residue left. Filtration works such that part of the mixture has smaller particles that can pass through the membrane of the filter paper while the bigger particles get stuck onto the paper as residue. A solution has a uniform size particle throughout and thus filtration does not work for purifying a solution.

Answer:Adding calcium to chicken's food is going to make the eggshells firmer. Independent variable:​

Explanation: