7th grade help me plzzzz

molecule(s)

two or more atoms touching means they are connected as molecules which also make up compounds

Answer:

The total heat required is 4088.6 J

Explanation:

We have three processes which involve heat absorption. We have to calculate the heat of each process and then to calculate the total heat.

1- liquid ethanol is heated from 25ºC (298 K) to the boiling point 78.5ºc (351.5 K). We use specifi heat of liquid ethanol to calculate the heat absorbed in this part:

H1= m x Sh x ΔT

H1= m x Sh x (Tfinal - Tinitial)

H1= 3.95 g x 2.45 J/g.K x (351.5 K -298 K)

H1= 517.7 JExplanation:

Answer:

The Answer is B

Explanation:

the total mass of the blocks would be the same apart as together.

a. The unit cell is the smallest group of atom which have overall symmetry of a crystal, and from which is the entire letters can be buled built up by repetition in 3 dimensions.

b. The volume(v) of the unit cell is equal to the cell edge length (a)cubed.

c. density of polonium is 9.32g/cm3.

Answer:

Correct

Explanation:

Balanced forces are always zero!

Answer:

Balanced

Zero

Explanation:

Answer:

Pb²⁺(aq) --> Ni²⁺(aq)

Explanation:

The equation of the reaction is given as;

Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)

In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.

We have;

Pb²⁺(aq)  + NO₃²⁻(aq) -->  Ni²⁺(aq)  + NO₃²⁻(aq)

Canceling the spectator ions;

Pb²⁺(aq) --> Ni²⁺(aq)

Answer:

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Explanation:

The complete ionic equation of this reaction is

Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)

The nitrate ions are spectator ions and can be removed from the equation, giving us

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Answer:

the answer is A

Explanation:

edg 2020

Answer:

the air above a wildfire/A

Explanation:

Answer: The monoatomic ions formed by bromine and rubidium are [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

Explanation:

When an atom accepts an electron negative charge is created on atom and is called as anion.  When atom loses an electron positive charge is created on atom and is called as cation.

The atomic number of bromine and rubidium is 35 and 37 respectively. So, the number of electrons is equal to 35 and 37 respectively. Bromine will gain one electron and rubidium will lose one electron to attain stable electronic configuration to form [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

[tex]Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]

[tex]Br^-:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

[tex]Rb:37:1s^22s^22p^63s^23p^64s^23d^{10}4p^63s^1[/tex]

[tex]Rb^+:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

Answer: The final concentration of a solution is 0.350 M

Explanation:

According to the dilution law,

[tex]C_1V_1=C_2V_2[/tex]

where,

[tex]C_1[/tex] = concentration of concentrated acid solution = 12.0 M

[tex]V_1[/tex] = volume of concentrated acid solution = 35.0 ml

[tex]C_2[/tex] = concentration of diluted acid solution= ?

[tex]V_2[/tex] = volume of another acid solution= 1.20 L = 1200 ml

( 1L=1000ml)

Putting in the values:

[tex]12.0\times 35.0=C_2\times 1200[/tex]

[tex]C_2=0.350M[/tex]

The final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L is 0.350 M

Answer:

C

Explanation: I think

Answer:

4.67M

Explanation:

The concentration of methanol (CH3OH) can be calculated using the following:

Molarity (M) = number of moles(n)/volume(v)

However, mole is not given. It can be obtained by using:

Mole = mass / molar mass

Where; mass = 34.4g

Molar mass (MM) of CH3OH is:

= 12 + 1(3) + 16 + 1

= 12 + 3 + 17

= 32g/mol

mole = 34.4/32

mole = 1.075mol

The volume needs to be converted to L by dividing by 1000

230mL = 230/1000

= 0.230L

Molarity = mol/volume

Molarity = 1.075/0.230

Molarity = 4.6739

Molarity = 4.67M

The concentration of CH3OH in solution is 4.67M

Im sorry but I have the same question tell me when you figure it out please

Answer:

The Second Law of Thermodynamics poses an insurmountable problem for ... More time will make things worse for the Darwinist, not better. ... error fail-safe and proof-reading devices utilized for quality control, assembly ... No one really supports the idea that the sun + non life = life

Explanation:

According to the second law of thermodynamics, the energy of the universe is conserved but the entropy of the universe is continuously increasing.

The second law of thermodynamics put some restrictions on the direction of heat transfer and attainable efficiencies of heat engines. This law stated that any spontaneously happening process will lead to an escalation in the entropy (S) of the universe.

This law explains that the entropy of an isolated system will never decrease with time. Mathematically, the 2nd law of thermodynamics:

ΔS (universe) > 0

where ΔS of the universe is the change in the entropy of the universe.

The second law of thermodynamics provides the criterion for the feasibility of any physical or chemical process. A physical or chemical process cannot take place unless it must follow both the 1st and 2nd laws of thermodynamics.

Learn more about second law of thermodynamics, here:

https://brainly.com/question/1604031

#SPJ2

Answer:

Yes, the equation (2 Na + H20. 2 NaOH + H2​ ) is a balanced equation.

Answer:

..............what.......

Answer:

hbyiy

Explanation:

Answer:

Mass of Fe produced = 4.468 g

Explanation:

Given data:

Mass of Fe produced = ?

Mass of Fe₂O₃ react = 6.50 g

Solution:

Chemical equation:

2Fe₂O₃        →     4Fe + 3O₂

Number of moles of Fe₂O₃ ;

Number of moles = mass/molar mass

Number of moles = 6.50 g/159.69 g/mol

Number of moles = 0.04 mol

Now we will compare the moles of iron and ironoxide.

                    Fe₂O₃             :             Fe

                         2                :              4

                       0.04             :             4/2×0.04 = 0.08 mol

Mass of iron produced:

Mass = number of moles × molar mass

Mass = 0.08 mol × 55.85 g/mol

Mass = 4.468 g

Answer:

Neutral atoms can be turned into positively charged ions by removing one or more electrons.

Explanation:

If there is an atom that has 9 protons and 9 electrons, removing an electron from the atom will gain a postive charge.

Answer:

for electricity, watts as in back to the future "1.21 jigga watts"!

Explanation:

Answer:

Same

Absorbed

Explanation:

When you are dealing with solutions the best way to tell that something has been absorbed is when the solution and the beam color are the same, since they have the same color you can be sure that the color has been absorbed properly and the greatest absorbance has occured.

The fill in the blanks should be filled with the same and absorbed.

The following information should be considered:

Therefore we can conclude that the fill in the blanks should be filled with the same and absorbed.

Learn more: brainly.com/question/362440

Answer: ea sports

Explanation:

A compound is a substance that contains two or more elements chemically combined in a fixed proportion. However, it is not an element because it can be broken down into simpler substances – carbon and hydrogen. ... Recall that the components of a mixture can be separated from one another by physical means.

Answer:

The Pressure Temperature Law. This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. With an increase in temperature, the pressure will go up.

Explanation:

Answer:

i dont

Explanation:

Answer:cookie

Explanation:

Answer:

1. Least

2. Most

Answer:

1st one is less 2nd is greater

Explanation:

Answer:

See explanation

Explanation:

The reaction is shown in the image attached. This reaction occurs by a carbocation (ionic) mechanism.

The lone pair on the nitrogen atom attacks the carbocation leading to the formation of the product as shown in the image attached.

Since the reaction occurs in a 1:1 ratio, two moles of reactants yields two moles of product.

Answer:

Accuracy is the closeness of a measured value to the accepted or exact value. The precision of a tool is the smallest unit of measure the tool provides. The smaller the units a tool can measure, the more precise the tool. A measurement can be precise and not be accurate.

Explanation:

Answer:

Kindly check the explanation.

Explanation:

NADH is oxidized anaerobic conditions by lactate dehydrogenase because in order to transform or change Pyruvate into Lactate it has to happen in an anaerobic condition that is where we hardly find oxygen(in the presence of no oxygen).

The chemical compound or say the enzyme known as lactate dehydrogenase gets its proton from NADH( in a REDOX type reaction). After getting the proton from NADH, it uses that to convert Pyruvate into Lactate.

NB: the conversion can also be done in aerobic condition but more ATP will be produced. With anaerobic condition, less ATO is produced and there is re-oxidation.