An ice cube melting is a physical change b. An ice cube melting is a chemical change c. Paper burning is a physical change d. Paper burning is a chemical change e. Bubbles forming when soda pop is poured into a glass is a physical change f. Bubbles forming when soda pop is poured into a glass is a chemical change g. Hard-boiling an egg is a physical change h. Hard-boiling an egg is a chemical change

Answer:

When ΔS > 0 and ΔH < 0, the process is always spontaneous as written. When ΔS < 0 and ΔH > 0, the process is never spontaneous, but the reverse process is always spontaneous. When ΔS > 0 and ΔH > 0, the process will be spontaneous at

Explanation:

What are the best conditions to lead towards a spontaneous reaction? high negative enthalpy, high temp, high positive entropy. Your enthalpy is high and negative but your entropy is also negative.

Answer:

3 Protons, 2 Neutrons, & 3 Electrons. Is the charge of this atom positive, negative, or neutral?

Explanation:

Put these atoms in order from most negative overall charge to least negative

overall charge.

11 Atom X: 104 protons, 102 electrons

11 Atom B: 24 protons, 18 electrons

1 Atom Q: 15 protons, 16 electrons

11. Atom P: 7 protons, 10 electrons

Explanation:

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Answer:

Explanation:

human obtains energy by eating food. as food is digested n broken down in our digestive system, energy is released to our body.

Answer:

Explanation:

Lead Monoxide: PbO

Nitric Acid: HNO3

PbO + 2 HNO3 ---> Pb(NO3)2 + H2O

Answer:

Explanation:

mono mean single so lead monoxide is PbO

nitric acid is HNO3

both Pb n O are double-charged while H n NO3 are single

so balanced eqn is:

PbO + 2HNO3 -> Pb(NO3)2 + H2O

Answer:

Unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Explanation:

Living things made up of a cell are called unicellular beings. They are very small and simple. In other words, unicellular organisms are those that are formed only by a single cell in which all the vital functions necessary for life are produced. For this reason, they are mostly microscopic organisms. Examples of unicellular organisms are viruses or bacteria.

Multicellular organisms are made up of a large number of cells. They present, therefore, a greater complexity than unicellular organisms in terms of the functions they develop. All current multicellular organisms come from a single cell, that is, they begin their life being unicellular. That is, they are formed from a zygote. Some examples of multicellular organisms are mammals, fungi, and mosses.

So, unicellular organisms consist of only one cell and multicellular organisms consist of many cell.

Answer:

Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium while environmental chemistry is the study of chemical processes that occur in water, air, terrestrial and living environments, and the effects of human activity on them. 

Physical chemistry is the area of chemistry that deals with how materials interact and change. The scientific study of chemical and biological phenomena that take place in the environment is known as environmental chemistry.

Physical chemistry attempts to quantify, correlate, and explain the quantitative features of reactions by focusing, in contrast to other branches, on the physics principles that underlie all chemical interactions (such as the gas laws).

While environmental chemistry is the study of chemical species' sources, reactions, movement, impacts, and fates in the air, soil, and water environments, as well as the impact of human activity and biological activity on these, can be summed up as the field of chemical ecology.

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(1) Seven electrons

1s² 2s²2p³

There are two electrons in the 2s subshell and three in the 2p subshell. The remaining two electrons are in the inner 1s subshell.

(2) 22 electrons

1s² 2s²2p⁶ 3s²3p⁶ 4s²3d²

There are two electrons in the 4s subshell and two in the 2p subshell. The remaining 18 electrons are in the inner subshells.

(3) 17 electrons

1s² 2s²2p⁶ 3s²3p⁵

There are two electrons in the 3s subshell and five in the 2p subshell. The remaining 10 electrons are in the inner subshells.

(4) n = 4, l = 2

(5) N=2 I=0 MI=0

(6) There can be two electrons in one orbital maximum. The s sublevel has just one orbital, so can contain 2 electrons max. The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max.

(7) n = 4 can hold up to 16 electrons

There are 4 sublevels; 42, 4p, 4d and 4f

4s (1 orbital), 4p (3 orbitals)

4d (5 orbitals), 4f (7 orbitals)

Maximum number of electrons in energy level: 16

s = 1 orbital

p = 3 orbitals

d = 5 orbitals

f = 7 orbitals

Add these up;

1 + 3 + 5 + 7 = 16

(8) 14 electrons If l = 3, the electrons are in an f subshell. The number of orbitals with a quantum number l is 2l + 1, so there are 2×3 + 1 = 7 f orbitals. Each orbital can hold two electrons, so the f subshell can hold 14 electrons.

sorry i didn't do the last two.. also sorry if some or none of these are correct, i tried my best

Balanced chemical equation for above reaction :

[tex] \mathrm{Cu +2 \: AgNO_3 \longrightarrow Cu(NO_3)_2 + 2 \: Ag}[/tex]

This is a displacement reaction, where copper (Cu) being morereactive than Silver (Ag) displaces Silver from its compound " Silver Nitrate " to form " Copper Nitrate " and silver .

[tex]\mathrm{✌TeeNForeveR✌}[/tex]

Answer:

3.01×10²⁶ molecules

Explanation:

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

Mass of H₂ = 1 Kg

Number of molecules =?

From Avogadro's hypothesis,

1 mole of H₂ = 6.02×10²³ molecules

But 1 mole of H₂ = 2 × 1 = 2 g

Now, we shall determine the number of molecules present in 1 Kg (i.e 1000 g) of H₂ as follow:

From Avogadro's hypothesis,

2 g of H₂ = 6.02×10²³ molecules

Therefore,

1000 g of H₂ = 1000 × 6.02×10²³ / 2

1000 g of H₂ = 3.01×10²⁶ molecules

Thus, the number of molecules present in 1 Kg (i.e 1000 g) of H₂ is 3.01×10²⁶ molecules

Viruses are known as obligatory parasites as they only become active and multiply when inside a host. Viruses are inactive when they are outside.

Answer:

B.Thermal insulation minimizes energy loses to the atmosphere.

Explanation:

It is important because it helps to stop hit from transferring from the calorimeter to the environment. This would help to have an accurate measurement of the heat that was used in the chemical process. The greatest cause of error that happens in calorimetry is when heat is lost to the environment. To reduce this, you insulate the calorimeter and add a cover.

Answer:

the red arrow shows that the change in enthalpy is positive

From the energy diagram, it is clear that, the enthalpy of the reaction is positive and it is an endothermic reaction.

An endothermic reaction is a chemical reaction that absorbs heat from its surroundings, resulting in a decrease in temperature of the surroundings. In other words, energy is taken in by the reaction from the environment.

During an endothermic reaction, the reactants absorb energy in the form of heat, light, or electricity to break the bonds between their atoms and form new bonds to create products.

The amount of energy absorbed by the reactants is greater than the energy released by the products. This energy difference is usually expressed as the enthalpy change (∆H) of the reaction, which is positive for endothermic reactions.

Here, the energy of products is higher than that of reactants and hence option A is correct.

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Both have Giant Covalent Structures, resulting in very high melting temperatures. However each carbon atom in Diamond has 4 covalent bonds with other Carbons, making it extremely strong and hard. On the other hand, each carbon in graphite is bonded to three carbons, and therefore graphite is formed in layers.

Answer:

B

pls correct me if im wrong

Answer:

When gases in containers are heated, their molecules increase in average speed. This means that they exert a greater force when they collide with the container walls, and also collide with the walls more frequently. The gas is therefore under greater pressure when its temperature is higher.

Using the idea of the  molar volume of butane gas, we have 2.23 moles of water vapor.

The term reaction equation shows the conversion of reactants to products. First of all, we must get down the reaction equation as follows;

C4H10(g) + 13/2O2(g) ----> 4CO2 (g) + 5H2O(g)

From the balanced reaction equation;

1 mole of  butane gas yields 5 moles of water vapor. Since 1 mole of butane gas occupies 22.4 L. Hence;

22.4 L of butane yields 5 moles of water vapor

10 L of butane gas yields 10 L * 5 moles/22.4 L = 2.23 moles

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Answer:

aefhfcjd

Explanation:

Answer:

i am so sorry. i do not have a answer but i am trying to find questioms i can answer

Answer:

39.02amu

Explanation:

According to this question, there are four (4) isotopes for element X with the following relative abundance:

Isotope 1 = 9.67%, mass no: 38

Isotope 2 = 78.68%, mass no: 39

Isotope 3 = 11.34%, mass no: 40

Isotope 4 = 0.31%, mass no: 41

To find the average atomic mass of element X, we multiply each isotopes' relative abundance by its mass no and find the sum as follows:

We convert each percentage to decimal abundance:

Isotope 1 = 9.67% = 0.0967

Isotope 2 = 78.68% = 0.7868

Isotope 3 = 11.34% = 0.1134

Isotope 4 = 0.31% = 0.0031

(0.0967 × 38) + (0.7868 × 39) + (0.1134 × 40) + (0.0031 × 41)

3.6746 + 30.6852 + 4.536 + 0.1271

Average atomic mass = 39.02amu

Answer: Yes! you're all good. Alkali metals in group 1 are the most metallic :)

Answer:

0.250L of solution. 0.250 moles of solute.

Explanation:

As you can see in the image, there is a beaker with an amount of solution. 1/2L are 500mL and each line of the beaker represents 100mL. That means the volume of the solution is approximately 250mL = 0.250L

Molarity is an unit of concentration defined as the moles of solute per liter of solution. A solution that is 1.000M contains 1.000 moles of solute per liter of solution.

As the volume of the solution is 0.250L, the moles are:

0.250L * (1.000mol/L) = 0.250 moles of solute

Answer:

any 5 ways to prevent earth are:

1.using ( 3R) principles Reduce, reuse, and recycle.

2.Educate yourself

3.Conserve water resources and other natural resources

4.Use long-lasting light bulbs.

5.stop deforestation and start afforestaion

Answer:

1807.24L

Explanation:

Using combined gas law equation:

P1V1/T1 = P2V2/T2

Where;

P1 = pressure on Earth

P2 = Pressure on Mars

V1 = volume on Earth

V2 = volume on Mars

T1 = temperature on Earth

T2 = temperature on Mars

According to the information provided of the balloon in this question;

P1 = 1 atm

P2 = 4.55 torr = 4.55/760 = 0.00599atm

V1 = 14.5L

V2 = ?

T1 = 19°C = 19 + 273 = 292K

T2 = -55°C = -55 + 273 = 218K

Using P1V1/T1 = P2V2/T2

1 × 14.5/292 = 0.00599 × V2/218

14.5/292 = 0.00599V2/218

Cross multiply

14.5 × 218 = 292 × 0.00599V2

3161 = 1.74908V2

V2 = 3161 ÷ 1.74908

V2 = 1807.24L

Answer:

Organ System

Explanation:

These organs are helping each other process food and therefore be an Organ System

Answer:

3. The mass of ethanol required is approximately 0.522869 g

The mass of ethanoic acid required is approximately 0.68156 g

4. The mass of iron (III) oxide required is approximately 285.952.189.095 tonnes

5. The mass of silver nitrate required is approximately 14.53 grams

6. The mass of copper oxide that would be needed is approximately 31.86 grams

7. a. The mass of the precipitate, Zn(OH)₂ formed is approximately 49.712 grams

b. The mass of the precipitate, Al(OH)₃ formed is approximately 13 grams

c. The mass of the precipitate, Mg(OH)₂, formed is approximately 14.579925 grams

Explanation:

3. The 1 mole of ethanol and 1 mole of ethanoic acid combines to form 1 mole of ethyl ethanoate

The number of moles of ethyl ethanoate in 1 gram of ethyl ethanoate, n = 1 g/(88.11 g/mol) = 1/88.11 moles

∴ The number of moles of ethanol = 1/88.11 moles

The number of moles of ethanoic acid = 1/88.11 moles

The mass of ethanol = (46.07 g/mol) × 1/88.11 moles = 0.522869 g

The mass of ethanoic acid in the reaction = 60.052 g/mol × 1/88.11 moles ≈ 0.68156 g

4. 1 mole of iron(III) oxide reacts with 1 mole of CO₂ to produce 1 mole of iron

The number of moles in 100 tonnes of iron= 100000000/55.845 = 1790670.60614 moles

The mass of iron (III) oxide required = 159.69 × 1790670.60614 = 285952189.095 g ≈ 285.952.189.095 tonnes

5. The number of moles of NaCl in 5 grams of NaCl = 5 g/58.44 g/mol = 0.0855578371 moles

The mass of silver nitrate required, m = 169.87 g/mol × 0.0855578371 moles ≈ 14.53 grams

6. The number of moles of CuSO₄·5H₂O in 100 g of CuSO₄·5H₂O = 100 g/(249.69 g/mol) ≈ 0.4005 moles

The mass of copper oxide required, m = 79.545 g/mol × 0.4005 moles ≈ 31.86 grams

7. a. The number of moles of NaOH in the reaction = 20 g/(39.997 g/mol) ≈ 0.5 moles

2 moles of NaOH produces 1 mole of Zn(OH)₂

0.5 moles of NaOH will produce 0.5 mole of Zn(OH)₂

The mass of 0.5 mole of Zn(OH)₂ = 0.5 mole × 99.424 g/mol = 49.712 grams

The mass of the precipitate, Zn(OH)₂ formed = 49.712 grams

b. 6 moles of NaOH produces 2 moles Al(OH)₃

20 g, or 0.5 mole of NaOH will produce (1/6) mole of Al(OH)₃

The mass of the precipitate, Al(OH)₃ formed, m = 78 g/mol×(1/6) moles = 13 grams

c. 2 moles of NaOH produces 1 mole of Mg(OH)₂, therefore;

20 g or 0.5 moles of NaOH formed (1/4) mole of Mg(OH)₂

The mass of the precipitate, Mg(OH)₂, formed, m = 58.3197 g/mol × (1/4) moles = 14.579925 grams

Answer:

Explanation:

i will show in details how 2 do the 1st Q n u can do the rest by following the way how it is done

3. given C^2H^5OH + CH^3CO^2H → CH^3CO^2C^2H^5 + H^2O

molar ratio of ethanol, ethanoic acid and ethyl ethanoate is 1 : 1 : 1

so mass = no. of moles * molecular mass

for same no. of moles, mass / molecular mass is the same

molecular mass of CH^3CO^2C^2H^5 = 12+1*3+12+16*2+12*2+5*1 = 88

molecular mass of C^2H^5OH = 12*2+1*5+16+1 = 46

molecular mass of CH^3CO^2H = 12+1*3+12+16*2+1 = 60

1 g of ethyl ethanoate = 1/88 mole

it requires 1/88*46 = 0.5227 g of ethanol; and

1/88*60 = 0.6818 g of ethanoic acid

to react together to form 1 g of ethyl ethanoate

Answer:

Narcotics

I think ans is

Explanation:

tropicaia

Ecstasy, also known as MDMA, is used recreationally, so it can be called a club drug. However, it is illegal in the US, so it would be considered a narcotic as well. The effects it has are also of the stimulant variety, so they would fall under that category as well. It is definitely not a depressant.

Answer:

v = 3,000,000,000 m/s

Explanation:

v = f *L

v = 3,000,000 * 1000

v = 3,000,000,000 m/s

Answer:

-2,802.960 kJ

Explanation:

The dimensional equation of the given quantities is presented as follows;

(6 mol) × (-393.5 kJ/mol) + (6 mol) × (-285.83 kJ/mol) - (1 mol) × (-1,273.02 kJ/mol) = ? kJ

The equation, can be written as follows;

[tex]\left (6 \times (-393.5) \, mol \times \dfrac{kJ}{mol} \right ) + \left(6 \times (-285.83) \, mol \times \dfrac{kJ}{mol} \right) - \left (1 \times (-1,273.02) \, mol \times \dfrac{kJ}{mol} \right) = ?[/tex]We note that [tex]mol \times \dfrac{kJ}{mol} \right) = kJ[/tex], therefore, the above equation becomes;

[tex]\left (6 \times (-393.5) \ kJ\right ) + \left(6 \times (-285.83) \ kJ \right) - \left (1 \, \times (-1,273.02) \ kJ \right) = -2,802.960 kJ[/tex]

Answer:

C. ((6 mol)(-393.5 kJ/mol) + (6 mol)(-285.83 kJ/mol)) - (1 mol)(-1,273.02 kJ/mol)

Explanation:

Got it right on edge.
: the one after is -2803.

Answer:

See explanation

Explanation:

Calcium carbide reacts with water to yield acetylene gas and calcium hydroxide as follows;

CaC2(s)+2H2O(g)⇋Ca(OH)2(s)+C2H2(g)

This now shows us that the equation as written in the question is wrong. Since the equation for the reaction of calcium carbide and water as shown in the question is wrong, the equation can not be balanced.