Which process is an example of a chemical change?
a. cooking a steak
b. chopping a tree
c. heating a cup of tea
d. drying clothes in the dryer

Answer: The correct option is A ( Break the crackers into pieces.)

Explanation:

The rate of reaction between two substances can be affected by the following factors:

--> surface area of reacting substances

--> concentration

--> reaction mechanism

--> temperature

--> the presence of a catalyst and

--> pressure ( if gaseous)

Reagents in solution tend to react faster than reagents in solid form. This is because molecules are freer to move about and collide more effectively in solutions. For example, a lump of zinc will not react as fast as powdered zinc with dilute hydrochloric acid to produce hydrogen. This is the same with the reaction between the crackers and soup. To increase the reaction of the substances, the crackers needs to be broken into pieces(thus,increased surface area)

Answer:

Two elements

Hydrogen and Oxygen

Answer:

: the average human-driven CO2 emissions per year climbed 1.4%

every household makes about 7 tons worth of Co2

A C02 footprints are produced at such high rates and hurts plants and the environment

B coal is a very inexpensive and efficient way to generate electricity. Since its a large quantity of them which still produces alot co2  unlike wood, burning wood doesn't  produce as much but it's much harder to ignite and get to last because it takes coal almost 100 degrees and wood takes about 700 degrees

The molecular mass of gas = 44 g/mol

Given

5.6 Liters of gas

11 gram of gas

Required

The molecular mass

Solution

STP = Standart Temperature and Pressure , 1 atm 273 K

At STP , 1 mol gas = 22.4 L

So mol of 5.6 Liters gas :

= 5.6 : 22.4

= 0.25 moles

The molecular mass of gas :

= mass : mol

= 11 g : 0.25 moles

= 44 g/mol

Answer:

The ranking of matter from the LEAST amount of energy to MOST amount of energy is;

B. Solid, Liquid, Gas

Explanation:

The kinetic energy of the particles that make of matter depends on the temperature of the particles and the particles are constantly vibrating

Solid state (Least amount of energy)

In the solid state, the matter is held in solid (rigid) crystal lattice and the particles are rigidly located next to other adjacent particles and stacked up layer by layer

Liquid state (Intermediate amount of energy)

As the temperature of the particles are increased by heating, the particles (atoms and molecules) gain more kinetic energy and their vibration is increased which on further heating, leads to the breaking of the lattice bond of the solid state and the particles are then readjusted to exist side by side rather than being stacked on one another and the assume the liquid state

Upon further heating the particles in the liquid acquire more energy and are  and rather than exist side-by-side, they are able to exist as individual particles in the gaseous form

Gaseous state (Most amount of energy)

From the kinetic theory of matter, the molecules of matter in the gaseous state contains enough energy which is more than the intermolecular forces of attraction such that the particles are able to move and occupy the entire volume of the container in which it is placed

Therefore, the correct option is Solid, Liquid, Gas.

Answer:

gas > liquid > solid

Explanation:

Because I said so,

And I took the test.

Explanation:

Homologous series are the series belonging to a series of aliphatic organic compounds that differ only by the addition of a CH2 group

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Answer:

Friction of wind against the ocean surface

Answer:

71%

Explanation:

Answer:

392g

Explanation:

The given compound is;

         Cr₂(SO₄)₃

To find the molar mass, we sum the atomic masses of the elements in the compounds together.

Atomic mass of Cr  = 52

                           S  = 32

                            O  = 16

So;

 Molar mass  = 2(52) + 3[32 + 4(16)]  = 392g/mol

Answer:

the molecules are moving more quickly

Explanation:

The  relationship between temperature and pressure is explained using the kinetic theory of matter.

As the temperature of the gas is increased, the molecules have a greater kinetic energy. This increased energy of the gas molecules make the collision between the molecules and with the walls of the container more rapid.

The correct option is;

the molecules are moving more quickly

Answer:

I just looked up the types of matter energy has.

Explanation:

I believe the answer is D.

Sally's list of matter that have energy is not complete as all the types of matter have energy as all matter have mass , and mass and energy are related, so she should have added gases and solids to her list.

Matter in chemistry, is defined as any kind of substance that has mass and occupies space that means it has volume .Matter is composed up of atoms which may or not be of the  same type.

Atoms are further made up of sub atomic particles which are the protons ,neutrons and the electrons .The matter can exist in various states such as solids, liquids and gases depending on the conditions of temperature and pressure.

The states of matter are inter convertible into each other by changing the parameters of temperature and pressure.

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Answer:

B  29 protons, 27 electrons

Explanation:

The given specie is copper ion:

         Cu²⁺  

We are to find the number of protons and electrons it contains.

 The number of protons is the positively charged particles in the atom.

 Electrons are the negatively charged particles in the atom.

The number of protons is the same as the atomic number

Atomic number of copper  = 29

 Number of protons  = 29

 Now;

    Charge  = Number of protons  - Number of electrons

     2  = 29  - number of electrons

     -27  = - number of electrons

 Number of electrons  = 27

Answer:

f = 0.94 ×10²⁴  Hz

Explanation:

Given data:

Frequency of light = ?

Wavelength of light = 3.2 ×10⁻¹⁶ m

Solution:

Formula:

Speed of light = wavelength × frequency

c = λ × f

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  = f × 3.2 ×10⁻¹⁶ m

f  =  3×10⁸ m/s   / 3.2 ×10⁻¹⁶ m

f  = 0.94 ×10²⁴ s⁻¹

f = 0.94 ×10²⁴  Hz (Hz = s⁻¹)

Answer:

2 Answers. This would be chemical energy that is converted to heat. The heat from the wick melts the wax which gets absorbed in the wick and then gets burnt (which is really oxidation) to produce heat energy as well as light energy.

Explanation:

A candle must undergo a chemical reaction in order to burn, producing heat and light. As a result, energy changes from chemical energy to heat and light energy. As a result, as a candle burns, chemical energy is transformed into heat and light energy.

Chemical energy is the energy that is released when chemical substances engage in a chemical reaction and change into other substances. Batteries, food, and gasoline energy are some instances of chemical energy storage media.

A type of potential energy associated with the structural organization of atoms or molecules is known as chemical potential energy. Chemical connections or interactions between molecules may have led to this configuration.

They are broken down into simpler molecules, such as glucose and amino acids, which are then either reassembled and stored in various forms, such as glycogen, or consumed as energy. Chemical energy in food is essential for giving our bodies the fuel they require to keep us alive and active.

Thus, energy changes from chemical energy to heat and light energy.

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Answer:

B. They are highly reactive.

Explanation:

Answer:

B: They are highly reactive

Explanation:

Sodium(Na) and potassium(K) are in the same family/group which is the Alkali Metal group.  These groups have their ability to displace H2(g) from water and create a basic solution. Alkali metals are also known to react violently and explosively with water. This is because enough heat is given off during the exothermic reaction to ignite the H2(g). Therefore, they are similar because of their reactivity.

Hope I helped!

Answer:

1. Hydrogen gas react with nitrogen gas to produce ammonia.

2. Phosphorus react with oxygen to produce phosphorus pentoxide

3. Iron react with water to produce hydrogen gas and Iron(III) oxide

4. Aluminum react with chlorine to produce aluminum chloride.

5. Zinc sulphide react with oxygen to produce Zinc(II) oxide and Sulphur dioxide

Explanation:

1. H₂ + N₂ —> NH₃

H₂ => Hydrogen

N₂ => Nitrogen

NH₃ => Ammonia

The word equation is:

Hydrogen gas react with nitrogen gas to produce ammonia.

2. P₄ + O₂ —> P₂O₅

P₄ => Phosphorus

O₂ => Oxygen

P₂O₅ => Phosphorus pentoxide

The word equation is:

Phosphorus react with oxygen to produce phosphorus pentoxide

3. Fe + H₂O —> H₂ + Fe₂O₃

Fe => Iron

H₂O => water

H₂ => Hydrogen gas

Fe₂O₃ => Iron(III) oxide

The word equation is:

Iron react with water to produce hydrogen gas and Iron(III) oxide.

4. Al + Cl₂ —> AlCl₃

Al => Aluminum

Cl₂ => Chlorine gas

AlCl₃ => Aluminum chloride

The word equation is:

Aluminum react with chlorine to produce aluminum chloride.

5. ZnS + O₂ —> ZnO + SO₂

ZnS => Zinc sulphide

O₂ => Oxygen

ZnO => Zinc(II) oxide

SO₂ => Sulphur dioxide

The word equation is:

Zinc sulphide react with oxygen to produce Zinc(II) oxide and Sulphur dioxide

Answer:

32.73%

Explanation:

To solve this problem, first find the molar mass of Al(OH)₃.2H₂O

 Atomic mass of Al  = 27g/mol

                            O = 16g/mol

                            H  = 1g/mol

Molar mass = 27 + 3(16 + 1) + 2(2(1) + 16)

                    = 27 + 51 + 36

                   = 114g/mol

Percentage composition  = [tex]\frac{36}{114}[/tex] x 100 = 32.73%

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.

This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.

C - Carbonates => CaCO₃(s) => CaO + CO₂

O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)

A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)

C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)

H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)

E - Electrolysis => see above electrolysis of NaCl(l)

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

a. t = 4.33 s

b. R = 53.04 m

c. H = 22.97 m

Given

vo=initial velocity=24.5 m/s

Angle = θ = 60°

Required

(a) time of flight, (b) range, and (c) maximum height.

Solution

Parabolic motion

a. time to flight

t = (2vo sin θ) / g

t = (2 x 24.5 x sin 60) / 9.8

t = 4.33 s

b. range (horizontal range) :

R = (vo² sin2θ )/g

R =(24.5² sin 120)/9.8

R = 53.04 m

c. maximum height

H = (vo²sin²θ)/2g

H = (24.5²sin²60)/2.9.8

H = 22.97 m

Answer:

87% bromine and 13% magnesium

Explanation:

The compound contained 32.0 grams of bromine and 4.9 grams of magnesium.

We need to find its percent composition.

Mass of the sample = mass of bromine + mass of magnesium

= 32 g + 4.9 g

= 36.9  g

Percentage composition of bromine,

[tex]\%=\dfrac{32}{36.9}\times 100\\\\=86.7\\\\=87\%[/tex]

The percentage composition of magnesium,

[tex]\%=\dfrac{4.9}{36.9}\times 100\\\\=13.27\\\\=13\%[/tex]

So, its percent composition is 87% bromine and 13% magnesium.

Answer:

Mass = 29.23 g

Explanation:

Given data:

Volume of solution = 814.2 mL 814.2/1000 = 0.8142 L)

Molarity of solution = 0.227 M

Mass of solute in gram = ?

Solution:

Molarity = number of moles / volume in L

By putting values,

0.227 M = number of moles / 0.8142 L

Number of moles = 0.227 M × 0.8142 L

Number of moles = 0.184 mol

Mass in gram:

Mass = number of moles × molar mass

Molar mass of calcium acetate = 158.17 g/mol

Mass = 0.184 mol × 158.17 g/mol

Mass = 29.23 g

Answer:

sodium carbonate

Explanation:

Sodium hydrogen carbonate (also known as sodium bicarbonate or bicarbonate of soda) has the chemical formula NaHCO3. When it is heated above about 80°C it begins to break down, forming sodium carbonate, water and carbon dioxide. This type of reaction is called a thermal decomposition.

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Answer:

O Trilobites

Explanation:

The first mass extinction that occurred between the Paleozoic and the Mesozoic era caused the extinction of the trilobites.

Extinction are catastrophic events that causes the loss of organisms on the earth surface. Several factors can lead to extinction.

Answer: addition and elimination

Explanation:

In addition you add and in elimination you remove (or subtract)

The reactions that are the reverse of one another are addition and elimination. Details about types of reactions are as follows.

A reaction is the transformation in which one or more substances is converted into another by combination or decomposition.

Reactions can be of different types as follows:

However, addition and elimination reactions are reverse of one another because addition involves adding substances while elimination involves removing substances.

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Answer:

3.81 [tex]\frac{1}{74.55}[/tex] X [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.08 X 10^22

Explanation:

74.55 is the mass