PLEASE HELP 30 POINTS PLS PLS

PLEASE HELP 30 POINTS PLS PLS

Answers

Answer 1
22-yes, they belong to the same group
23- they are metals
24-Atoms of group 1 elements all have one electron in their outer shell. This means Na and K have the same valence electrons.
25-Metals are solids at room temperature, therefore Na and K are solid.
26- mass number=A=235
Protons=z=92
Neutrons=mass number-protons
Neutrons=A-Z
Neutrons=235-92
Neutrons=143

Related Questions

What is h+ concentration associated with a pH=10.2
A. 10.9
B. 6.3*10^-11
C. 3.1
D. 3.2 * 10^-3

Answers

Answer:

6.3*10^-11

no reasoning i just know thats the answer you dont have to trust me.

help people i really need this

Answers

Option “A” is the crest of the wave because it’s the maximum value of upward displacement within a cycle.

Given that C = n/V. And you have n=2 and C=4 what does V= ??
1...0.5
2...2
3...4
4...8
or5...Dont know​

Answers

I thinks it’s 3.....4

Calculate the number of molecules in 100. g of O2 *

Answers

I am pretty sure the answer is 6.25 molecules
See picture for explanation

How do I tell my crush I like them...

Answers

Answer:

You can tell them on April Fools and if they reject you just say April Fools.

Answer: if u do it on text just say oh wrong person or something I’m not sure

Explanation:

It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). A 45.91 gram sample of a hydrate of MnSO4 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 37.07 grams of the anhydrous compound remained. What is the formula of the hydrate

Answers

Answer: The formula of the hydrate is [tex]MnSO_4.2H_2O[/tex]

Explanation:

Decomposition of hydrated manganese sulphate is given by:

[tex]MnSO_4.xH_2O\rightarrow MnSO_4+xH_2O[/tex]

Molar mass of [tex]MnSO_4[/tex] = 151.0 g/mol

According to stoichiometry:

(151.0+18x) g of [tex]MnSO_4.xH_2O[/tex] decomposes to give 151.0 g of [tex]MnSO_4[/tex]

Thus 45.91 g of [tex]MnSO_4.xH_2O[/tex] decomposes to give= [tex]\frac{ 151.0}{151.0+18x}\times 45.91g[/tex]  of [tex]MnSO_4[/tex]

Also we are given : 37.07 g of  [tex]MnSO_4[/tex] is produced

Thus we can equate the two equations:

[tex]\frac{ 151.0}{151.0+18x}\times 45.91=37.07[/tex]

[tex]x=2[/tex]  

Thus the formula of the hydrate is [tex]MnSO_4.2H_2O[/tex]

depression what are the effects to the brain

Answers

Depression can affect a person psychologically, it also has the potential to affect physical structures in the brain. These physical changes range from inflammation and oxygen restriction, to actual shrinking. Depression can impact the central control center of nervous system. Depression can cause amygdala to enlarge. This is a part of the brain associated with emotional responses. When amygdala becomes larger and more active, it causes sleep disturbances, changes in activity levels, and changes in other hormones.

Do molecules move in all phases? (yes/no)

Answers

Answer: sorta

Explanation:

In fact, they do not flow at all: they simply vibrate back and forth. Because the atoms in a solid are so tightly packed, solid matter holds its shape and cannot be easily compressed

A student places 2 mL of 2% ethanolic silver nitrate solution into test tube. They add 2 drops of an unknown compound into the test tube while gently mixing. After five minutes, the student heated the test tube in a water bath and a white precipitate formed. They added 2 drops of 1 M nitric acid to the mixture which was cooled to room temperature and still noticed the precipitate did not dissolve in response to the nitric acid. What compound is most likely the unknown

Answers

Answer:

hi

Explanation:

i am smart but i need this app cuz some are realy hard

Use the following balanced reaction to solve:
P4 (s) + 6H2 (g) → 4PH3 (g)

How many grams of phosphorus trihydride will be formed by reacting 60 L of Hydrogen gas with an excess of P4?

Answers

Answer:  60.7 g of [tex]PH_3[/tex] will be formed.

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given volume}}{\text{Molar volume}}[/tex]    

[tex]\text{Moles of} H_2=\frac{60L}{22.4L}=2.68moles[/tex]

The balanced chemical reaction is

[tex]P_4(s)+6H_2(g)\rightarrow 4PH_3(g)[/tex]

[tex]H_2[/tex] is the limiting reagent as it limits the formation of product and [tex]P_4[/tex] is the excess reagent.

According to stoichiometry :

6 moles of [tex]H_2[/tex] produce = 4 moles of [tex]PH_3[/tex]

Thus 2.68 moles of [tex]H_2[/tex] will produce=[tex]\frac{4}{6}\times 2.68=1.79moles[/tex]  of [tex]PH_3[/tex]

Mass of [tex]PH_3=moles\times {\text {Molar mass}}=1.79moles\times 33.9g/mol=60.7g[/tex]

Thus 60.7 g of [tex]PH_3[/tex] will be formed by reactiong 60 L of hydrogen gas with an excess of [tex]P_4[/tex]

what is hydrogen ion concentration of an acid solution whose PH is 3.4?​

Answers

It’s easy, if the PH of any acidic solution = -Log[H+], where [H+] is hydrogen ion concentration, multiply each term by (-1) then raise each term as a power to (10), so it will become like this:-
[H+] = 10^(-PH)

Solubility is the mass in a given volume of a substance.
True
False

Answers

Answer: True

Explanation:

Calculate the [H+] concentration for a solution with a pH of 6.4

Answers

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Answer: 3.98 x 10^-7

Explanation:

I hope this helped!

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- Zack Slocum

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Which environment can occur for a short while and usually found in low level areas along rivers, lakes, and streams?

Desert
Mountain
Rainforest
Wetland

Answers

the answer is wetland

Answer:The answer is wetland or rainforest

Explanation:

It’s wetland or rainforest because its with the tropical zone and there will be no such thing as desert and mountain have those but the rainforest is with the tropic to so Goodluck with any of your test and hope this did not make sense xdd

Chromium is manufactured by heating a mixture of chromium(III) oxide with aluminium powder.
Cr2O3(s) + 2Al(s) → 2Cr(s) + Al2O3(s)

a=Calculate the mass of aluminium needed to react with 50 g of Cr2O3.
b=Calculate the mass of chromium produced from 50 g of Cr2O3.
c=Calculate the mass of chromium produced from 5 kg of Cr2O3.
d=Calculate the mass of chromium produced from5 tonnes of Cr2O3.

Note: 1 tonne = 1,000,000 g
Ar: Cr = 52, O = 16, Al = 27

Answers

I’m taking a good estimation and gonna say B but I’m torn between that and D

Which compound is more soluble in water at 25°C?
A.
MgF2 (Ksp = 5.2 x 10-11)
B.
SrF2 (Ksp = 7.9 x 10-10)
C.
AgBr (Ksp = 5.0 x 10-13)
D.
Agl (Ksp = 1.5 * 10-16)

Answers

Answer:

B

Explanation:

The solubility depends on the ksp. As the value of ksp increases the compound becomes more and more soluble.

In the options, the highest ksp value is 10^-10, thus that one is the most soluble.

Which is a similarity between a fish embryo and a bird embryo in the early stages of development?
Gill slits
forelimbs
jaw bones
hindlimbs

Answers

Hindlimbs should be the answer

Answer:

Gill Slits

Explanation:

For the one who asked what hind limbs are they are back legs :)

For each of the solutions from above order the following in increasing polarity (from lowest to highest): solvent, more polar molecule, less polar molecule, silica gel. If the difference cannot be determined, indicate this by entering N/D. Note you might have to use a bit of logic and consider the properties of each. Useful information is found in the lab manual and student guide.
Solution % %Ethyl Lowest Next Lowest Next Highest Highest Number Hexane Acetate Polarity Polarity Polarity Polarity 1 100 0 4 75 25 3 50 50 5 5 25 75 2 0 100

Answers

Answer:

Solvent, less polar molecule, more polar molecule, silica gel

Explanation:

Solvent has lowest polarity but less polar molecule has more polarity than solvent. The more polar molecule has higher polarity value whereas silica gel has the highest polarity. The polarity of compounds is due to the difference of electronegativity values of the elements that bonded with each other. The difference of electronegativity value is high between silicon and oxygen is responsible for high polarity of silica gel.

How does pollution affect Earth Systems.


ILL GIVE BRAINLIEST!!!!!!​

Answers

Answer:

pollution causes smog

Smoke fog, or smog for short, is a type of intense air pollution.

it makes GHG wich is greenhouse gas and it makes the smog to stay inside the earth wich heats the Earth and it causes flood, storm, tornadoes, ect.

Does Borax pure substance?

Answers

Answer:

Borax is a natural mineral with a chemical formula Na2B4O7 • 10H2O. Borax also is known as sodium borate, sodium tetraborate, or disodium tetraborate. It is one of the most important boron compounds. The International Union of Pure and Applied Chemistry (IUPAC) name for borax is sodium tetraborate decahydrate.

what happens when ?? Fresh red flower is introduced into a vessel contain Sulphur dioxide along
with moisture.​

Answers

Answer:

Sulphur dioxide is a good reducing agent, hence it can easily decolourise substances in the presence of water. Therefore, when rose petals are placed in a jar containing sulphur dioxide, they get decolourised..!!

Hopefully u will satisfy with my answer..!!Please Mark on brainleast please..!!

1) Give all the mole-to-mole relationships (ratios) that exist in fraction form for the following reaction. (12 total) 2 Li2O2 + 2 CO2 2 Li2CO3 + O2​

Answers

Answer:

1 mol Li₂O₂/mol CO₂ or 1 mol CO₂/mol Li₂O₂

2 mol Li₂CO₃/mol O₂ or 1 mol O₂/2 mol Li₂CO₃

1 mol Li₂O₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol Li₂O₂

2 mol Li₂O₂/mol O₂ or 1 mol O₂/2 mol Li₂O₂

1 mol CO₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol CO₂

2 mol CO₂/mol O₂ or 1 mol O₂/2 mol CO₂

Explanation:

The balanced chemical equation is:

2 Li₂O₂ + 2 CO₂ → 2 Li₂CO₃ + O₂

The mole-to-mole relationships are provided by the chemical stoichiometric coefficients (2 for Li₂O₂, 2 for CO₂, 2 for Li₂CO₃ and 1 for O₂).

We have to relate the moles of 1 compound to the moles of another compound in the equation. So, we can start writing the relationships between reactants (Li₂O₂ and CO₂)

2 moles of Li₂O₂ react with 2 moles of CO₂ → 2 mol Li₂O₂/2 mol CO₂= 1 mol Li₂O₂/mol CO₂ or 1 mol CO₂/mol Li₂O₂

Now, the relationships between products (Li₂CO₃ and O₂):

2 moles of Li₂CO₃ are produced when 1 mol of O₂ produced → 2 mol Li₂CO₃/1 mol O₂= 2 mol Li₂CO₃/mol O₂ or 1 mol O₂/2 mol Li₂CO₃

Finally, between reactants and products:

2 moles of Li₂O₂ produce 2 moles of Li₂CO₃ → 2 mol Li₂O₂/2 mol Li₂CO₃= 1 mol Li₂O₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol Li₂O₂

2 moles of Li₂O₂ produce 1 mol of O₂ → 2 mol Li₂O₂/1 mol O₂= 2 mol Li₂O₂/mol O₂ or 1 mol O₂/2 mol Li₂O₂

2 moles of CO₂ produce 2 moles of Li₂CO₃ → 2 mol CO₂/2 mol Li₂CO₃= 1 mol CO₂/mol Li₂CO₃ or 1 mol Li₂CO₃/mol CO₂

2 moles of CO₂ produce 1 mol of O₂ → 2 mol CO₂/1 mol O₂= 2 mol CO₂/mol O₂ or 1 mol O₂/2 mol CO₂

If 43.1 g of O2 and 6.8 g of CO2 are placed in a 13.7 L container at 34 degrees C, what is the mixture of gasses?
answer must be in atm

Answers

Answer:

The total pressure of the gas mixture = 2.76 atm

Note: The question is not complete. The complete question is as follow:

If 43.1 g of O2 and 6.8 g of CO2 are placed in a 13.7 L container at 34 degree Celsius , what is the pressure of the mixture of gases?

Explanation:

Mass of O₂ gas = 43.1 g, molar mass of O₂ gas = 32.0 g/mol

Number of moles of O₂ gas = 43.1/32.0 = 1.347 moles

Mass of CO₂ gas = 6.8 g, molar mass of CO₂ gas = 44.0 g

Number of moles of CO₂ gas = 6.8/44 = 0.155 moles

Total number of moles of gas mixture, n = (1.347 + 0.155) = 1.502 moles

Volume of gas mixture, V = 13.7 L

Temperature of gas mixture, T = 34 °C = (273.15 + 34) K = 307.15 K

Pressure of gas mixture = ?

Molar gas constant, R = 0.0821 liter·atm/mol·K.

Using the ideal gas equation: PV =nRT

P = nRT/V

P = (1.502 × 0.0821 × 307.15) / 13.7

P = 2.76 atm

Therefore, the total pressure of the gas mixture = 2.76 atm

7x[(7+7)divide7]

PLEASE HELP

Answers

Answer:

ik this isnt the answer but mathwa will solve all yours problems

Explanation:

When 577 J of energy is added to 32.3 g of aluminum at 17.4ºC, the temperature increases to 46.6ºC. What is the specific heat of aluminum?

Answers

Answer:

0.612 J/g°C

Explanation:

Using the formula as follows:

Q = m × c × ∆T

Where;

Q = amount of heat (Joules)

m = mass of substance (g)

c = specific heat capacity (J/g°C)

∆T = change in temperature (°C) i.e. final - initial temperature

According to the information provided in this question;

Q = 577 J

m = 32.3 g

c = ?

Final temp = 46.6ºC, initial temp. = 17.4°C

∆T = (46.6 - 17.4) = 29.2°C

Using Q = m × c × ∆T

c = Q ÷ m.∆T

c = 577 ÷ (32.3 × 29.2)

c = 577 ÷ 943.16

c = 0.6117

c = 0.612 J/g°C

can you help me please I would love that ​

Answers

Answer:

what are you confused on?

What is Heat? What is Cold?

Answers

Answer:

Heat is the process of something getting hot(temperatures going up). Cold is when something gets cold(temperature decreases).

Explanation:

Which of the following is a homogeneous mixture ?A.pizza B.oxygen
C.tea
D .pure water

Answers

I think it would be d bc water is everywhere

The force of gravity can act between two people.
True or false??

Answers

False

Gravitational force is the force between two bodies irrespective of the presence of any objects between them,

In the reaction 2 H, Ł02 → 2 H, O, what is the mole ratio of hydrogen to water?
A 2:2
B 2:1
C 1:2
D 4:4

Answers

A

because both have 2's in front of them

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