I thought in the third shell there are 18 electrons, but why are they gaining only 2 electrons?? Pls tell me... I have exam tomorrow....

[tex] \LARGE{ \boxed{ \rm{ \purple{Required \: answer}}}}[/tex]

☃️ Chemical formulae ➝ [tex]\sf{CaCO_3}[/tex]

How to find?

For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

[tex] \boxed{ \sf{No. \: of \: moles = \frac{given \: weight}{molecular \: weight} }}[/tex]

And, Then we need to find the number of molecules which can be found by:

[tex] \large{ \boxed{ \sf{no. \: of \: molecules = N_A \times no. \: of \: moles}}}[/tex]

Here, Na = Avagadro Number (6.022 × 10²³)

☀️ As it is a compund, We considered molecules. Then, we can predict the no. of atoms of elements in one molecule of compound and get the answer.

Solution:

Atomic weight of elements:

❍ Molecular weight of [tex]\sf{CaCO_3}[/tex]

= 40 + 12 + 3 × 16

= 52 + 48

= 100 g/mol

❍ Given weight: 10 g

Then, no. of moles,

⇛ No. of moles = 10 g / 100 g mol‐¹

⇛ No. of moles = 0.1 moles

☄ No. of moles of Calcium carbonate in the given weight = 0.1 moles

Finding no. of molecules,

⇛ No. of molecules of CaCO3 = 0.1 × 6.022 × 10²³

⇛ No. of molecules of CaCO3 = 6.022 × 10²²

Now,

Then, 6.022 × 10²² molecules will have,

= 3 × 6.022 × 10²² atoms of oxygen

= 18.022 × 10²² atoms of oxygen

In more scientific form,

= 1.8022 × 10²³ atoms of oxygen

☄ Hence, Final answer - 1.8022 × 10²³ atoms

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Answer:

Explanation:

Physical hazard means a chemical for which there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive) or water-reactive.

EXPLODE:  

to expand with force and noise because of rapid chemical change or decomposition, as gunpowder or nitroglycerine (opposed to implode).

to burst, fly into pieces, or break up violently with a loud report, as a boiler from excessive pressure of steam.

I found this information:

Anaerobic respiration begins the same way as fermentation. The first step is still glycolysis, and it still creates 2 ATP from one carbohydrate molecule. However, instead of ending with glycolysis, as fermentation does, anaerobic respiration creates pyruvate and then continues on the same path as aerobic respiration.

After making a molecule called acetyl coenzyme A, it continues to the citric acid cycle. More electron carriers are made and then everything ends up at the electron transport chain. The electron carriers deposit the electrons at the beginning of the chain and then, through a process called chemiosmosis, produce many ATP. For the electron transport chain to continue working, there must be a final electron acceptor. If that acceptor is oxygen, the process is considered aerobic respiration.

Scientists believe that fermentation and anaerobic respiration are older processes than aerobic respiration.

I hope this help. :)

have a good day!

Answer:

chemistry

Explanation:

Answer:

C

Explanation:

The reactions:

[tex] \mathrm{Mg(NO_3)_2 \longrightarrow MgO+ 2NO_2 +O_2}\\

\mathrm{Mg(OH)_2 \longrightarrow MgO + H_2O}\\

\mathrm{MgCO_3 \longrightarrow MgO +CO_2}[/tex]

Explanation:

this may help u follow me and mark as brainlist PlZzzzz

a)

A: Copper

B: CuO

C: [tex]\mathrm{CuSO_4}[/tex]

D: $\mathrm{CuCO_3}$

E: $\mathrm{CO_2}$

F: $\mathrm{Cu(NO_3)_2}$

b)

$\mathrm{CuO+ H_2SO_4}\rightarrow \mathrm{CuSO_4 + H_2O}$

c)

$\mathrm{CuCO_3+ 2HNO_3}\rightarrow \mathrm{Cu(NO_3)_2+ CO_2+ H_2O}$

Answer:

The other person was correct =w0

Explanation:

Answer:

It is Physics

because these are all physical components and/or characteristics

-Biology is the study of life

-Earth science is the study of the biosphere we live in

-Astronomy is about space

Answer:

Physics

Explanation:

Physics is the study of motion and force...

Biology is the study of life

Earth Science is wind, water and uk...

Astronomy is about planets and stars

Answer

A is the answer

Answer:

B. The water must gain thermal energy from its surroundings.

Explanation:

Boiling is the process whereby a substance is changed from a liquid state to a gaseous state due to the application of heat. For boiling to be achieved, a liquid substance must reach or exceed its boiling point, which is the specific temperature at which a specific liquid boils.

For this change of state i.e. from liquid to gas, to occur, atoms or molecules of the liquid must gain kinetic energy and move faster. However, this kinetic energy cannot be attained without a rise in temperature, which causes the molecules to gain THERMAL ENERGY or heat energy and move fast. Thermal energy is the energy that arises from a hot substance.

Therefore, for water to boil at a given pressure, it must gain thermal energy from its external surroundings, which causes its molecules to have an increased kinetic energy and move faster. This fast movement of the molecules causes the transition of phases (from liquid to gas).

Answer:

I got 0.01 moles, hope this helps!

Answer:

formed by burns rises quickly hydorogen

[tex] H_2+\frac12O_2 \longrightarrow H_2O[/tex]

I don't think I need to name the product.

this reaction is very exothermic. so the gases and the flames are very hot, i.e. very lighter (hot air rises) than the normal air. so it rises quickly

Answer:

Explanation:

The number of moles of a substance can be found by

[tex]n = \frac{m}{M} [/tex]

where

n is the number of moles

M is the molar mass

m is the mass of the substance

To find the number of moles we must first find the molar mass

Chemical formula for calcium oxide is

So the molar mass of CaO is

M( CaO) = 40 + 16 = 56 g/mol

Mass of CaO = 5.0g

Substitute the given values into the formula

The number of moles in 5.0g of calcium oxide is

[tex]n = \frac{5 \: g}{56 g/mol} [/tex]

We have the final answer as

Hope this helps you

[tex] \LARGE{ \boxed{ \pink{ \rm{Answer}}}}[/tex]

☃️ Chemical formulae ➝ [tex]\sf{CaO}[/tex]

For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]

Atomic weight of elements:

❍ Molecular weight of [tex]\sf{CaO}[/tex]

= 40 + 16

= 56 g/mol

❍ Given weight: 5 g

Then, no. of moles,

⇛ No. of moles = 5 g / 56 g mol‐¹

⇛ No. of moles = 0.089 moles [tex]\approx[/tex] 0.09 moles

⚘ No. of moles of Calcium oxide in the given weight = 0.09 moles approx.

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Answer:

A

Explanation:

Density: water>ice>methanol

Ice is lighter than methanol hence it is able to float on it. However, ice is denser than water hence it sinks.

Answer:

The answer is A.

Explanation:

The density of ice in methanol must be different from that in water.

Answer:

d

Explanation:

The arrangement of electrons in an atom

Answer:

D. Arrangement of electrons in an atom.

Explanation:

K L M N O P Q

2 8 8 18 18 32 50

The path where electrons revolve is called orbits.

Hope his helps ;) ❤❤❤

The number of protons define what element we're dealing with.

Answer: The number of protons define what element we're dealing with.

Answer:

for number 2

Explanation:

Hydrogen. Hydrogen ignites in air. If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop.

Molar mass is defined by the ratio of the mass to the moles. The molar mass of zinc (Zn) in the periodic table is said to be 65.38 g/mol. Thus, option D is correct.

Molar mass is the mass of the element or the compound in one mole of the given substance. It is denoted in units gm/ mol. The units come from the ratio of mass in grams to the moles in mol.

It is used to calculate the amount of the substance present in the mole of the substance and can be expressed as particles, like ions, or molecules with the help of Avogadro's number.

The molar mass or the atomic mass of the zinc element is denoted in the periodic table. The mass is written on the lower side of the element symbol.

Therefore, the molar mass of zinc (Zn) is 65.38 g/mol.

Learn more about molar mass here:

https://brainly.com/question/27669728

#SPJ5

Answer:

Usually you have V, for voltage, Ohms for resistance, and Coulombs for charge.

Explanation:

See the image attached :)

Answer:

4.36g XY

I hope it helps!

Answer:

We mean this by '4R principle'

The question may be about ' 3R' principle....

Answer:

Solar Eclipse happens when the moon gets between the sun and the earth, the moon gets all the light and blocks the earth from getting sunlight.

Hope this helps ;) ❤❤❤

Answer:

A. Stable

Explanation:

unless ur talking about the star in your PFP, then it's unstable xd

Answer:c

Explanation:

Answer:

A). The complementary shapes of an enzyme and a substrate.

Explanation:

The Lock-and-key mechanism was proposed by Emil Fischer for the first time and characterized as the metaphor which helps in elucidating the specificity of the enzymatic reactions. In this metaphor, the lock is described as the enzyme while 'key' is characterized as the substrate which the enzyme acts upon. If the key is not appropriately sized, it will not fit into the active site i.e. the keyhole of the lock or enzyme and reaction will not take place. Thus, option A is the correct answer.

Answer:

Answer: mountains not sure

Water is chemical

Box is physical

Lion is physical

Hope this helped!!

Explanation:

Answer:

x contain 9 percent ofcalcium carbonaye

Answer:

The statements that accurately  describe how the assumptions affects scientific thinking are;

People think that the Earth is flat, so they think that it is only safe to travel certain distances from a given location.

People think that the Earth is flat, so think that when the Sun sets, it does underneath the Earth

Explanation:

The proof that the Earth is round was made by the Greek philosopher, Aristotle, over 2,000 years ago, by observation of the change in the constellation of the stars as a person changes his position North or South

The initial belief was that the Earth is flat disc surrounded by water, while the it was believed that the shape of the Earth was that of a square with four mountains at the vertices that support the sky from falling.

Answer:

Explanation:

1- Cathode 2- copper electrolyte solution usually (CuSO4) 3- Cu half cell 4- bulb (when lighted, shows the current is flowing) 5- Zn half cell 6- Zn electrolyte solution 7- connecting wires 8- anode (Zn) 9-salt bridge

2- the copper-(Cu) electrode is the cathode and the zinc-(Zn) electrode will be the anode. This is because the cathode is negatively charged (while Cu is positively charged, so it attracts) and the anode is positively charged (while Zn will be negative)

3- the electrons flow from the anode, where oxidization takes place, to the cathode, where reduction reactions take place.

That's the best i can do. Hope it helps.

Answer:

Explanation:

• Label all parts (1–9), including the solutions in each beaker and the connecting tube.

1. Copper strip

2. Cu2+(aq) (copper electrolyte solution or copper nitrate)

3. Cathode compartment  

4. Light bulb  

5. Anode compartment  

6. Zn2+ (aq) (zinc electrolyte solution or zinc nitrate)  

7. The connecting wires or the external circuit  

8. Zinc strip  

9. Salt bridge  

• Label which cell is the cathode and which cell is the anode. Include the charge on each strip.

The copper strip is the cathode and the zinc strip is the anode. The anode is positively charged and the cathode is negatively charged. This is because the cathode attracts a positive charge and the anode attracts a negative charge.  

• Show, or describe in detail, the flow of electrons.

The atoms from the zinc strip are oxidized into zinc ions, (the anode is where oxidation occurs). The electrons in the anode then travel through the wire to the copper strip. The electrons then merge with the copper ions in the solution creating copper metal (the cathode is where reduction occurs).  

• Describe what type of electrochemical cell is pictured. Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.  

This is a voltaic or galvanic cell. It works by using spontaneous oxidation-reduction reaction to generate electricity.  

Zn(s) --- Zn2 + (aq) + 2e-  

Cu2 + (aq) + 2e- --- Cu(s)