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4 years ago

Hi please Help me in my hww

Chemistry

1 answer:

omeli [17]4 years ago

8 0

1) is C because the arrows are pointing in so that means to squeeze
3) is A as the picture shows the dropper

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Severe droughts cause some lands to become deserts, and this process leads to

Alona [7]

All above

Severe Droughts can make land unlivable, as all living things need food and water to survive

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3 years ago

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The company's chief financial officer recognizes the need for an upgrade to the smart watches but does not understand why the bu

goldenfox [79]

Answer:

how about you just put whats on your mind and continue on

Explanation:

no need to ask this question just answer it and move on or you will lose your sanity trying to figure this out

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3 years ago

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What heavier element is created when hydrogen atoms fuse together in the sun’s core?

sergey [27]

Answer:

Helium is created from hydrogen in the sun's core.

Four hydrogen-1 nuclei fuse to produce

one helium-4 nucleus, two neutrons,
two positrons, and
two electron neutrinos.

Explanation:

Step One:

${\rm ^1_1 H + ^1_1 H\to ^2_1 H + e^{+}} + v_e$ .

Two hydrogen-1 nuclei fuse. One proton will convert to a neutron. The products will be

one hydrogen-2 nucleus,
one positron, and
one electron neutrino.

Step Two:

$\rm ^1_1 H +^2_1 H \to ^3_2 He$ .

There are plenty of hydrogen-1 nuclei available in the core of the sun. The hydrogen-2 nucleus from step one will fuse with a hydrogen-1 nucleus. The product is

one helium-3 nucleus.

Step Three

$\rm ^3_2 He + ^3_2 He \to ^4_2 He + ^1_1 H + ^1_1 H$ .

Two helium-3 nuclei from step two react with each other. The products are:

one helium-4 nucleus, and
two hydrogen-1 nuclei.

The overall reaction will be:

${\rm 6\; ^1_1 H \to ^4_2 He + 2\; ^1_1 H+2\; e^{+}}+v_\text{e}$ .

${\rm 4\; ^1_1 H \to ^4_2 He + 2\; e^{+}} + v_\text{e}$

In other words, hydrogen nuclei in the core of the sun fuse together to form helium.

6 0

3 years ago

how many coefficients need to be changed to make this chemical equation balanced? Zn + HNO3 --> Zn (No3)2 + H2

mestny [16]

Coefficient 2 should be placed in the equation before the nitric acid in the reactant so that the chemical reaction becomes balanced.

The given chemical reaction is,

Zn + HNO3 --------> Zn (No3)2 + H2

Here, the elements Hydrogen, Nitrogen, and Oxygen are unbalanced.

These elements are altogether found in HNO₃ on the reactant side and are found as nitrate and hydrogen gas on the product side.

To balance the equation, the coefficient 2 is to be added in the reactant side so that 2 moles of Hydrogen, Nitrogen, and Oxygen would be balanced with 2 moles of Nitrate and two moles of Nitrogen.

On adding 2 on reactant side, we get

Zn + 2HNO3 -----------> Zn(NO3)₂ + H₂

This gives us a balanced equation and thus the equation could be balanced this way.

Therefore, coefficient 2 is to be added to make the equation to be balanced.

To know more about the balanced equation, click below:

brainly.com/question/26694427

#SPJ1

8 0

1 year ago

An aqueous solution that is 20.0 percent sulfuric acid (h2so4) by mass has a density of 1.105 g/ml. determine the molarity of th

GuDViN [60]

The definition of molarity is:

Molarity = moles of solute / total volume of solution in Liters

In this case, our solute is Sulfuric Acid. To solve this problem, let us assume a basis for calculation.

Let us say that,

Total mass of solution = 100 g

Therefore mass of H2SO4 = 20 g

The molar mass of H2SO4 = 98.079 g / mol

Calculating for number of moles of H2SO4:

number of moles = 20 g / (98.079 g / mol)

number of moles = 0.204 mol

Calculating for the volume of solution using the density:

total volume of solution = 100 g / (1.105 g / mL)

total volume of solution = 90.50 mL = 0.0905 L

Therefore the molarity is:

Molarity = 0.204 mol / 0.0905 L

Molarity = 2.2542 mol / L

Molarity = 2.25 M

3 0

4 years ago