BRAINLLEST! Boiling water for mac and cheese is a physical change. Give 2 pieces of evidence to support this claim

Answer:

B. One or more phase change occur

C. the final state of substance is liquid

D. the sample initially gas

Explanation:

The pressure p = 1.00 atm

The temperature t = 149.2K

The temperature > 119.8K

119.8K being the normal boiling point.

This shows that the krypton is a gas

After it has cooled the pressure = 1.00 atm

The temperature T dropped to 107.8K

T < 115.9K

The melting point has been put as 115.9K

This is a liquid. The final state of the substance is a liquid. Since the temperature is less than the melting point and the pressure is 1.00 atm

Answer:

true mark me brainlist

Explanation:

Answer:

Part 1-B

Part 2-D

Part 3-A

Answer:

1.B

2.D

3.A

Explanation:

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Answer:

The attractive force between the sodium and chloride ions has a magnitude of -2.94 x 10⁻⁹ N

Explanation:

An electron is a negatively-charged particle. The charge on an electron is -1.6 x 10⁻¹⁹ C. This is also known as the fundamental unit of charge, e. A proton has the same charge as as electron but its charge is positive.

The charge on the chloride ion is negative and is due to an electron whereas the charge on the sodium ion is positive and is due to a proton.

The magnitude of the force of attraction between two charges is given by the Coulomb's law: F = Kq₁q₂/r²

where K is a constant = 9 x 10⁹ N.m₂.C⁻², q₁ = -1.6 x 10⁻¹⁹ C, q₂ = +1.6 x 10⁻¹⁹ C, r = 0.28 nm = 0.28 x 10⁻⁹ m

F = {(9 x 10⁹ N.m₂.C⁻²) (-1.6 x 10⁻¹⁹ C) (+1.6 x 10⁻¹⁹ C)} / (0.28 x 10⁻⁹ m)²

F = -2.94 x 10⁻⁹ N

Therefore, the attractive force between the sodium and chloride ions has a magnitude of -2.94 x 10⁻⁹ N

Answer:

2.66 g of Fe, can be obtained from the reaction

Explanation:

Let's think the reaction:

2Fe₂O₃   +  6CO  →   4Fe +  6CO₂

Ratio is 2:4, so If i have x moles of iron (III) oxide, I will produce the double of moles of Fe.

Mass / Molar mass = Mol

3.80 g / 159.7 g/m = 0.0237 moles

0.0237 moles . 2 = 0.0475 moles

Molar mass Fe = 55.85 g/m

Mol . Molar mass = Mass → 0.0475 m . 55.85 g/m = 2.66 grams

Explanation:

Answer:

5 its just what i do

Explanation:

Answer:

C. The gills allow the fish to take in oxygen from the water.

Answer: C- one should have high electron affinity and the other low ionization energy.

Explanation:

Ionization energy is the energy required to remove the electron from an isolated gaseous atom.

Electron affinity is the tendency of an isolated atom to attrcat the electrons towards itsellf.

An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and it can donate electron easily if it has low ionization energy.

The element which accepts the electrons is known as electronegative element or non metal and it can easily accept the electron if it has high electron affinity.

Answer: As a consequence, chemical equations must be balanced, meaning that the number and kinds of atoms must be the same on both sides of the reaction arrow. The numbers placed in front of formulas to balance equations are called coefficients, and they multiply all the atoms in a formula.

because they need a medium to travel they can travel everywhere if they got the medium

B) loses electrons and is oxidised

Its oxidation number is 0 in Co(s) and +2 in Co(C2H302)2(aq), hence it gets oxidised

In the reaction as mentioned below:-

[tex]Co(s) + Ni(C2H302)2aq -- > Co(C2H3O2)2aq + Ni(s)[/tex]

As shown in reaction cobalt losses elections so the reaction is oxidised.  Thus, option b is correct.

Oxidation is a type of reaction in which loss of electrons and gain of protons is takes place during a reaction by molecules, atom or ion. Oxidation takes place when the oxidation state of a molecule, atoms or ion is increased.

The opposite reaction is called as reduction in which gains of electron and loss of protons is takes place . In reduction reaction the oxidation state of molecules, atoms or ion is decreased.

Oxygen has been added to a compound as an older method of oxidation.  Although oxygen is typically added to a compound in compliance with the loss of electrons requirements and the oxidation state increase.

Therefore, we can say that in the reaction

[tex]Co(s) + Ni(C2H302)2aq -- > Co(C2H3O2)2aq + Ni(s)[/tex]

As shown in reaction cobalt losses elections so the reaction is oxidised.  Thus, option b is correct.

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Answer:

True

Explanation:

Answer: True

Explanation:

Answer:

A. catalyst.

Explanation:

Catalyst is something that causes things to decay. I think catalyst is the right answer from what i know from Miraculous Ladybug... Did you know the show was originally going to be an anime?

Answer:

Silver

Explanation:

Given parameters:

Mass = 116g

Energy  = 511J

Initial temperature  = 21.6°C

Final temperature  = 40.5°C

Unknown:

Specific heat capacity and the type of metal = ?

Solution:

To solve this problem, we need to find the specific heat capacity of the metal given,

         H  = m x c x Ф  

H is the energy

m is the mass

c is the specific heat capacity

Ф is the change in temperature

        511  = 116 x c x (40.5 - 21.6)

         511  = 2192.4c

           c  = 0.233J/g°C

The specific heat capacity of silver is similar to this.

Answer:

READ THE EXPLAINATION

Explanation:

It says show your work.

40.5°C – 21.6°C = 18.9°C

So, the metal was raised 18.9 deg Celsius.  

It took 511 J of energy to raise the metal 18.9 deg Celsius.

511/ 18.9 = 27.03  

It takes 27.03 J to raise 116 g of the metal 1 degree.    

27.03/116 = .233

It takes .233 J to raise 1 gram of the metal 1 degree.

Therefore, the specific heat capacity of the metal is .233 J

According to the Specific heat values table, Silver has a specific heat capacity of .233.

The metal is silver.  

The mass of the boat is equal to the mass of the liquid which is displaced by placing the boat in the liquid.

Archimedes' Principle states that the buoyant force of the object is equal to the weight of the water which is displaced by the boat. If the weight of the water that is displaced by the boat is less than that of the weight of the boat, then in this case the boat sinks. Archimedes' principle or the buoyant force is very useful for the calculation of the volume of an object that does not have a regular shape.

The mass of the displaced liquid is always equal to the volume of the liquid multiplied by the density of the fluid. When a boat is placed in the water, the volume of displaced water is equal to the mass of the boat which is placed in it.

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Answer:

i. 3 moles.

ii. 132.03 grams.

iii. 105.6 grams.

Explanation:

Hello!

In this case, given the balanced chemical reaction, we can proceed as follows:

i. By starting with 5 moles of oxygen, via the 5:3 mole ratio we compute the produced moles of CO2:

[tex]n_{CO_2}=5molO_2*\frac{3molCO_2}{5molO_2} =3molCO_2[/tex]

ii. Now, since we have previously computed the moles of CO2 from the same moles of oxygen, by using its molar mass (44.02 g/mol), we obtain:

[tex]m_{CO_2}=3molCO_2*\frac{44.01gCO_2}{1molCO_2} =132.03gCO_2[/tex]

iii. Now, we need to combine the previously used two proportional factors for the calculation of the mass of CO2 from 128.00 grams of oxygen (molar mass 32.00 g/mol):

[tex]m_{CO_2}=128.00gO_2*\frac{1molO_2}{32.00gCO_2}*\frac{3molCO_2}{5molO_2}*\frac{44.01gCO_2}{1molCO_2}\\\\m_{CO_2}=105.6gCO_2[/tex]

Best regards!

Answer:

Na2O (the 2 is small the o is not a 0 but and OOh)

Explanation:

Hey there, The formula for the compound formed between sodium and oxygen will be Na2O

Though since sodium is a metal and oxygen is a nonmetal, Na2O is expected to be ionic.

An ionic compound is a chemical compound made up of ions held together by electrostatic forces known as ionic bonding.

To determine an ionic compound's formula, first identify the cation and record its symbol and charge.

After that, identify the anion and record its symbol and charge. Finally, mix the two ions together to make an electrically neutral compound.

After two or more atoms lose or gain electrons to form an ion, an ionic bond can form.

Ionic bonds form when metals lose electrons and nonmetals gain electrons. Ions with opposite charges attract each other, forming an ionic bond.

The symbol for sodium is Na+, and the symbol for oxygen is O2. The resulting compound here in the given condition is Na2O.

Thus, this is the formula for the ionic compound formed between sodium and oxygen.

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Answer: Body plans change as new challenges arise.

Explanation:

The mollusks are the invertebrate animals. They live marine environment. They live in shallow waters. They have been found in variety of marine habitats so this indicates their adaptiveness to different conditions. They have body plan that comprises of shell, mantle, radula and muscular foot that helps in survival and adaptation in different conditions. The shell and mantle are hard structures which protect these animals from predators and also help them to camouflage. Also the muscular foot helps in locomotion. Radula helps in feeding. Oysters, snails are some examples of mollusks.

Mass (in g) of the excess reactant (P₄) left = 7.626 g

Given

Reaction

P4(s)+6Cl2(g)→4PCl3(l)

45.57 g P4 and 130.2 g Cl2

Required

mass (in g) of the excess reactant left

Solution

mol P₄ (MW=124 g/mol) :

45.57 : 124 = 0.3675

mol Cl₂(MW=71 g/mol) :

130.2 : 71 = 1.834

mol : coefficient of reactant : P₄ : Cl₂ :

= 0.3675/1 : 1.834/6

= 0.3675 : 0.306

Cl₂ as limiting reactant(smaller ratio)

Reacted mol of P₄ (as an excess reactant):

=1/6 x 1.834

= 0.306

Unreacted mol of P₄ :

= 0.3675 - 0.306

= 0.0615

Mass of P₄(left) :

= 0.0615 x 124

= 7.626 g

Answer:

2K   +   2H₂O   →   2KOH  + H₂

Explanation:

The reactants are:

    Potassium metal  = K

    Water  = H₂O

 The products are:

  Potassium hydroxide  = KOH

  Hydrogen gas  = H₂  

The reaction equation is given as;  

                Reactants   →   Products

        2K   +   2H₂O   →   2KOH  + H₂

The reaction is a single displacement reaction

Answer:

do you have a picture of the choices?

Answer:

Estoy deprimido y odio la vida. Así que sí

Answer:

oKaY?!

Explanation:

Answer - B Atoms in the original substances are arranged in a different way to make new substances

Answer:

Trial 1: Heat lost by the metal = -4100 J

Trial 2: Heat lost by the metal = -4042 J

Trial 3: Heat lost by the metal = -3940 J

Explanation:

Assuming that all of the heat lost by the metal  is transferred to the water and no heat is lost to the surroundings; Heat lost by metal = heat gained by water. Qmetal = -Qwater

Note: If the experiment was carried out in a calorimeter of known heat capacity, some heat is lost to the calorimeter.

Hence,  Qmetal = -(Qwater + Qcalorimeter)

Quantity  of heat, q = mass * specific heat capacity * temperature change

Trial 1

mass of water = 70.001 g

specific heat capacity of water = 4.184 J/g/°C

Initial temperature of water = 24.2 °C

final temperature of mixture = 38.2 °C

Temperature change of water = 38.2 - 24.2 = 14.0 °C

Heat gained by water = -(70.001 * 4.184 * 14.0) = -4100 J

Therefore, heat lost by the metal = -4100 J

Trial 2

mass of water = 70.008 g

specific heat capacity of water = 4.184 J/g/°C

Initial temperature of water = 24.0 °C

final temperature of mixture = 37.8 °C

Temperature change of water = 37.8 - 24.0 = 13.8 °C

Heat gained by water = -(70.008 * 4.184 * 13.8) = -4042 J

Therefore, heat lost by the metal = -4042 J

Trial 3

mass of water = 70.271 g

specific heat capacity of water = 4.184 J/g/°C

Initial temperature of water = 23.2 °C

final temperature of mixture = 36.6 °C

Temperature change of water = 36.6 - 23.2 = 13.4 °C

Heat gained by water = -(70.271 * 4.184 * 13.4) = -3940 J

Therefore, heat lost by the metal = -3940 J

The question is incomplete, the complete question is;

Silicon has three naturally occurring isotopes with thefollowing masses and natural abundances:

Isotope Mass ({\rm amu}) Abundance (%)

{\rm Si}-28 27.9769 92.2

{\rm Si}-29 28.9765 4.67

{\rm Si}-30 29.9737 3.10

Calculate the atomic mass of silicon.

Answer:

28.09 amu (to four significant figures)

Explanation:

Given that;

Isotope Mass  Abundance (%)

Si-28 27.9769 92.2

Si-29 28.9765 4.67

Si-30 29.9737 3.10

So we now have;

Relative atomic mass of silicon;

(27.9769  ×  0.9218)  +  (28.9765  ×  0.0471)  +  (29.9738  ×  0.0312)

25.789 + 1.365 + 0.9351 = 28.09 amu (to four significant figures)

Answer: in this ecosystem tuna fish are considered predators and small fishes are their prey.

Explanation: This is just an easy smart guess why? because the Tuna fish(predator) eat the small fishes(prey) as if what it looks like in the chart.

Im not sure about this question but i hope this helps

Answer:

in this ecosystem tuna fish are considered predators and small fishes are their prey.

Explanation:

Answer:

1.44 g/mL

Explanation:

total mass is mass of the flask plus mass of the solution

TM = Flask + H2O2

88.5 = 16.5 + x

x = 72.0 gram

density = mass/volume

H2O2 density = 72/50

= 1.44 g/mL