In a city, the buildings, streets, air,
and water are all ______
parts of the environment.

Answer:

2Mg(s) +O₂(g) → 2MgO(s)

Explanation:

Mg(s) +O₂(g) → MgO(s)

When a chemical equation is balanced, the number of atoms of each element is equal on both sides of the arrow. We usually balance O and H last.

In this case, the number of Mg atoms is equal on both sides. Thus, let's move on to balance the O atoms. On the left side, there are 2 O atoms, while there is only 1 O atom on the left side. Thus, write a '2' in front of MgO.

Mg(s) +O₂(g) → 2MgO(s)

Now, the number of Mg atoms is not equal. Write a '2' in front of Mg to balance it.

2Mg(s) +O₂(g) → 2MgO(s)

The equation is now balanced with 2 Mg atoms and 2 O atoms on each side.

Answer: The complete nuclear symbol will be [tex]_8^{18}\textrm {O}[/tex]

Explanation:

The nuclear symbol is written as: [tex]_Z^A\textrm {X}[/tex] where Z= atomic number , A = mass number X = symbol of element

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

For an electrically neutral atom,

Atomic number = Number of electrons = Number of protons = 8

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons  

Mass number = 8 + 10 = 18

Thus complete symbol will be [tex]_8^{18}\textrm {O}[/tex]

Answer:

C. Carbon dioxide has increased as a result of increased human activities.

Explanation:

THESE ARE THE OPTIONS FOR THE QUESTION BELOW

A. Carbon dioxide is emitted from fertilizers used in farming.

B. Other greenhouse gases trap more heat than carbon dioxide.

C. Carbon dioxide has increased as a result of increased human activities.

D. Carbon dioxide is emitted from commercial refrigeration.

Global warming can be regarded as

long-term heating of climate system of the Earth, this has been a point if observation even as far as pre-industrial period arround 1850. This global warming can be attributed to activities such as human activities as well as primarily fossil fuel burning, and as a result of this there is rise in heat-trapping, increase in greenhouse gas levels arround the atmosphere of the Earth. Human activities that brings about increase of Carbon dioxide concentration in the atmosphere are ;

✓ burning of oil as well as coal and gas,

✓deforestation

Hence, many scientists believe that carbon dioxide has likely contributed more to global warming than other greenhouse gases as a result of increase in Carbon dioxide which is as a result of increased human activities.

Greenhouse gas, any gas that has the property of absorbing infrared radiation (net heat energy) emitted from Earth's surface and reradiating it back to Earth's surface, thus contributing to the greenhouse effect. Carbon dioxide, methane, and water vapour are the most important greenhouse gases.

Answer:

C

Explanation:

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The endocrine system's role is to send out chemical messages so as to regulate bodily activities. It determines how and when you grow, when you hit puberty and how much your body changes, and even what mood you're feeling right now.

I really hope this helps!! :)

Answer:

Sentence type wish

The answer to the question: No.

Answer:

Will you join me for dinner tonight?

Explanation:

like and rate and brainiest plz

Answer:

See explanation

Explanation:

According to the law of conservation of energy; energy is neither created nor destroyed but is converted from one form to another.

This means that energy can not be lost, we can trace the transfer of energy between a system and its surroundings.

When a pot of water at 25°C is placed over a flame until it has boiled away, energy is transferred from the pot (the system) to the surroundings hence the temperature of the surroundings rises accordingly.

Answer:

Because the Earth's gravity acts on the atmosphere and holds it down, just as it does all other objects. The weight of the atmosphere is estimated to be about 5.75 quadrillion (5,750,000,000,000,000) tons. Air pressure is the "push" of the atmosphere on the Earth's surface.

Answer:

as for my answer is C.....

Answer:

Magnesium Hydroxide or Milk of Magnesia

Explanation:

The chemical sign for Magnesium is Mg, and OH automatically means Hydroxide.

Answer:

Special type of surface that repels liquid

Explanation:

Answer:

10-7mol/l

Explanation:

Answer: 10-7mol/l

Explanation:

BRAINS

Answer:

6. They all have the same number of molecules.

7. 19.5 g

Explanation:

6. From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules i.e

1 mole = 6.02×10²³ molecules

Considering the question given above, each compounds has just 1 mole. Thus, they will also have the same number of molecules.

7. Determination of the mass of iron (Fe)

Number of mole of Fe = 0.35 mole

Molar mass of Fe = 55.85 g/mol

Mass of Fe =?

Mass = mole × molar mass

Mass of Fe = 0.35 × 55.85

Mass of Fe = 19.5 g

Thus, the mass of 0.35 mole of iron (Fe) is 19.5 g

Answer: 3.83

Explanation:

Answer:

3.83 :)

Explanation:

:)

Answer:

someone people use Doppler radar

Explanation:

Answer:

We might need more information too answer that question...

Explanation:

Try Inserting A picture ️ :)

Answer: 156

Explanation:

Answer:

Water gradually degrades them until the metal parts rust and the other materials deteriorate.

Explanation:

Answer:

1) 4.21 x 10^24 molecules of Fe2O3

2) 36.416g of O2

Explanation:

1) First, find moles of Fe2O3 by using the mole ratio of 3:2. Fe2O3 has a coefficient of 2, and O2 has a coefficient of 3 thus making their mole ratio 2:3. Then, multiply 10.5 moles of O2 by 2/3 which equals 7 moles of Fe2O3. Finally, convert moles of Fe2O3 to molecules by multiplying it by Avogadro's number.

10.5 mol x 2/3= 7 mol Fe2O3

7 mol multiplied by 6.02 x 10^23 = 4.21 x 10^24 molecules

2) First, convert grams of KClO3 to moles by dividing it by its molar mass(approximately 122.5 g), which equals .759 mol. Then find moles of O2 by multiplying .759 mol KClO3 by the mole ratio of O2 to KClO3, which is 3:2. That equals 1.138 moles of O2. Finally, convert moles to grams by  multiplying 1.138 mol by the molar mass of O2 (approximately 32g). 36.416g of O2 is your final answer.

93g KClO3/ 122.5g = .759 mol KClO3

.759 mol x 3/2= 1.138 mol O2

1.138 mol x 32g= 36.416g O2

Answer:

See Explanations ...  I'll have to deliver my explanation in two posts. One is beyond the limits allowed.    

Explanation:

Stoichiometry is very easy if you understand the relationship between the 'mole' and the balanced chemical equation. Let's start by defining the 'mole'

The 'mole' of substance is the mass of substance (element or compounds) that contains 1 Avogadro's Number ( = 6.02 x 10²³ ) of particles. The mass of substance that does contain 1 Avogadro's Number of particles is 1 formula weight of substance (also, molecular weight of substance). That is,

1 mole = 1 formula wt. = 1 mole weight = 1 Avogadro's Number = 6.02 x 10²³ particles of substance.

So, assuming you can determine formula weight then that value expressed in terms of grams is a 'Gram Formula Weight'; that is, 1 GFW = 1 mole wt.

At this point it is assumed that you understand how to balance simple chemical equations by inspection. That is, by the Law of Mass Balance ...

total mass of reactants = total mass of products

In problem 1 you are given iron (Fe) + molecular oxygen (O₂) => iron(III) oxide (Fe₂O₃)  ...   4Fe + 3O₂ => 2Fe₂O₃   ... ∑mass R = ∑mass P.

Now, focus on the coefficients of each substance, that is, 4 for Fe, 3 for O₂ and 2 for Fe₂O₃. These values (coefficients) are moles of each substance in a special type of equation called the 'Standard Equation'. The Standard Equation is one which when balanced its coefficients are in the smallest whole number mole ratio of substance. That is the equation above is showing 4 moles of Fe, 3 moles of O₂ and 2 moles of Fe₂O₃.  This is  important in that most balanced equations that will be given in textbook problems will be in Standard Form.

From the Standard Form, the coefficients can be doubled, or divided in half, or whatever multiple or fraction one desires. The reaction would still perform in correct proportions. However, the multiples or fractions would not be in Standard Form. Most, if not all, stoichiometry problems will provide only the Standard Form.

Example, let's take the given equation above (from problem 1)

4Fe + 3O₂ => 2Fe₂O₃.

Both of the following are in correct proportions and will react with respect to the proportions YOU choose ...

(multiply by 2) => 8Fe + 6O₂ => 4Fe₂O₃.

(dividing by 2) => 2Fe + 3/2O₂ => Fe₂O₃.

Both are balanced and conform to the Law of Mass Balance but are not in Standard Form. Oh, and the Standard Form equations are assumed to be at 0°C and 1 atm, even if not specified in the problem. You may not need that now, but will become important in Gas Laws.

Let's move on to stoichiometry calculations. There are several methods being taught within the chemed. community, but I'm going to focus only on using mole ratios.  

My approach begins with this rule => convert reaction data to moles, solve using mole ratios and convert to needed dimension at the end of the problem. This will simplify a lot of problems once you understand what it's about.

OK, for problem 1 ...

How many molecules of Fe₂O₃ can be produced from 10.5 moles of O₂?

Given the Standard Form equation 4Fe + 3O₂ => 2Fe₂O₃.

Now, write (neatly) the equation and list the givens under the specific substances ...

             4Fe +       3O₂         =>     2Fe₂O₃.

              ex*     10.5 moles       ? molecules       note: ex* = excess (not used)

In this problem, since O₂ is already in terms of moles no conversion needed.

What you need to focus on is the relationship between the coefficients of O₂ and Fe₂O₃. Note that the coefficient of Fe₂O₃ is SMALLER than the coefficient of O₂. This means that the number of moles of Fe₂O₃ formed will be smaller than moles of O₂ given, that is 10.5 moles. How much smaller? Easy Calculation => Take the coefficient of O₂ and the coefficient of Fe₂O₃ and make a ratio of the numbers that will make 10.5 SMALLER. That is, you should use 2/3(10.5) to get a smaller number, not 3/2(10.5) because that would give a larger number and inconsistent with the ratio given in the balanced equation.      

So, moles of Fe₂O₃ produced = 2/3(10.5) moles Fe₂O₃ = 7 moles Fe₂O₃. Note that 7 moles is smaller than 10.5 moles.

Now, the number of molecules of Fe₂O₃ is also an easy calculation.

Remember that 1 mole contains 6.02 x 10²³ particles, then 7 moles would contain ...

= 7 moles Fe₂O₃  x  6.02 x 10²³ molecules Fe₂O₃/mole Fe₂O₃

= 4.21 x 10²⁴ molecules Fe₂O₃.  

Go to 2nd post for problem 2 solution.

Answer:

Corona

Explanation:

The outermost layer of the sun's atmosphere is called the corona, meaning “crown.” The corona is formed of thin wisps of gas that extend outward into space for millions of miles. It is much less bright than the photosphere, so we can only see it if the rest of the sun is blotted out, for example during a solar eclipse.

Answer:

decant/ filter then decompose the electrolytes by electrolysis

Explanation:

Differentiation of suspension solution is done by filtering and differentiation of electrolyte and non-electrolyte solution is done by electrolysis process.

Electrolysis process is used to decompose the any electrolyte present in any solution into their constitute ions towards the cathodes and anodes under the electric flow of current.

Process which is required to differentiate suspension solution is filtering, because in this solution suspended insoluble particles are present which get filtered. Now to differentiate between non electrolyte and electrolyte solution we will use the electrolysis process, as non electrolyte solution do not show any behavior in this.

Hence, we use filtering and electrolysis process for the differentiation.

To know more about electrolysis, visit the below link:
https://brainly.com/question/25712870

Answer:

Dipole interactions occur when partial charge form within a molecule because of the uneven distribution of electrons.polar molecules align so that the positive end of one molecule interacts with the negative end of another molecule.

Answer:  Uneven distribution of electrons in a      

               Molecule.

Explanation: Q. What’s the dipole-dipole interaction ?

SOL.-

CONCEPT-

Dipole-dipole Forces -

         Intermolecular interactions are necessary  for           the stability of the molecule. There are many types of intermolecular forces, and dipole-dipole forces are part of these forces them.

Dipole-dipole forces, also known as dipole-dipole interactions. The electrostatic forces between two permanent polar molecules is known as dipole- dipole force. Generally, the positive side of one molecule is attracted to the negative side of another molecule. The two molecules come closer, and add for increasing the stability of the substance. This type of interaction is different from a regular ionic bond or a covalent bond because there is no transfer or sharing of electrons.

Causes of a Dipole-dipole Interaction-

Dipole-dipole interaction arises due to the unlike distribution of electrons in a molecule. The electrons are assembled at one end of the molecule. Thus, the molecule get a partially negative charge at one end and a partial positive charge at the another end. That process making them polar. Generally, two polar molecules with opposite nature charges will  attract one another.

Diagram-    

Reference  link.- https://brainly.com/question/22790347

Project code-#SPJ2 

Answer:

C.Universal indicator turns orange in

weak acid.

Explanation:

option A and B are incorrect coz universal indicator turns red in strong acid and in strong alkali (base) it turns blue

Answer:

2)====We assume you are converting between moles CaCl2 and gram. You can view more details on each measurement unit: molecular weight of CaCl2 or grams This compound is also known as Calcium Chloride. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles CaCl2, or 110.984 grams

110.98 g/mol

The molar mass of CaCl2 is 110.98 g/mol.

3)The molar mass of Na3 PO4 is 163.9 g/mol. To determine the molar mass, add the atomic mass of all the atoms.

Answer: The coefficient is 3.645

The exponent is 1

There are 4 significant digits

The rightmost significant figure is 5

Explanation:

Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.

For example : 5000 is written as [tex]5.0\times 10^3[/tex]

According to avogadro's law, 1 mole of every gas contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles, occupy 22.4 L at STP and weighs equal to its molecular mass.

131.29 g of Xe occupy = 22.4 L at STP.

Thus 213.62 g of [tex]Xe[/tex] occupy = [tex]\frac{22.4}{131.29}\times 213.62=36.45L[/tex] at STP.

Scientific notation = [tex]3.645\times 10^1L[/tex]

The coefficient is 3.645

The exponent is 1

There are 4 significant digits

The rightmost significant figure is 5

Answer:

23 neutrones.

Explanation:

Bajo el modelo atómico actual, los átomos están hechos de neutrones (Particulas sin carga y número másico de 1), electrones (Partículas con carga de -1 y número másico de 0) y protones (Partículas con carga de +1 y número másico de 1).

El elemento contiene 22 electrones y carga neutra. Esto significa que contiene igual número de protones:

22 protones.

Como el número másico es de 45 y los protones aportarán solo 22 de número másico, el elemento debería tener:

23 neutrones para completar así, el número másico.

Answer:

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