Please help!! only right answers!! will mark brainlest.

Answer:

B

Explanation:

Answer:

The first 50 elements along with their valences are given below :

1. Hydrogen = 1

2. Helium = 0

3. Lithium = 1

4. Beryllium = 2

5. Boron = 3

6. Carbon = 4

7. Nitrogen = 3

8. Oxygen = 2

9. Fluorine = 1

10. Neon = 0

11. Sodium = 1

12. Magnesium = 2

13. Aluminium = 3

14. Silicon = 4

15. Phosphorus = 3

16. Sulphur = 2

17. Chlorine = 1

18. Argon = 0

19. Potassium = 1

20. Calcium = 2

21. Scandiun = 3

22. Titanium = 3

23. Vanadium = 4

24. Chromium = 3

25. Manganese = 4

26. Iron = 2

27. Cobalt = 2

28. Nickel = 2

29. Copper = 2

30. Zinc = 2

31. Gallium = 3

32. Germanium = 4

33. Arsenic = 3

34. Selenium = 2

35. Bromine = 1

36. Krypton = 0

37. Rubidium = 1

38. Strontium = 2

39. Yttrium = 3

40. Zirconium = 4

41. Niobium = 3

42. Molybdenum = 3

43. Technetium = 7

44. Ruthenium = 4

45. Rhodium = 3

46. Palladium = 4

47. Sliver = 1

48. Cadmium = 2

49. Indium = 3

50. Tin = 4

Note :

An element like Iron, copper can have more than one valencies.

Answer:

50 elements chemical eq, atomic number, atomic mass, no.of electrons, no.of protons, no.of neutrons, electronic configuration and valancies are given in the above attachment

Explanation:

Hope it helps you

Answer:

The new volume will be  

0.7 L

Explanation:

This is an illustration of Charles' law, some of the time called the temperature-volume law. It expresses that the volume of a gas is straightforwardly corresponding to the Kelvin temperature, while pressing factor and sum are held steady.  The condition is  V  1  T  1  =  V  2  T  2  , where  V  is volume and  T  is temperature in Kelvins.  Known  V  1  =  0.5 L  T  1  =  20  ∘  C  +  273.15  =  293 K  T  2  =  150  ∘  C  +  273.15  =  423 K  Obscure  V  2  Arrangement  Revise the condition to confine  V  2  . Substitute the known qualities into the condition and address.  V  2  =  V  1  T  2  T  1  V  2  =  (  0.5  L  ×  423  K  )  293  K  =  0.7 L  adjusted to one huge figure

Answer:

The approximate mass of the weight required is 348.3 kg

Explanation:

The dimensions of the dead-weight gauge are;

The pressure up to which the dead-weight gauge measures, P = 3,000 bar

The diameter of the piston of the dead-weight gauge, D = 4 mm = 0.004 m

The dead-weight gauge pressure formula is given as follows;

Pressure, P = The weight applied, W ÷ The area the weight is applied, A

∴ The weight applied, W = P × A

Where;

P = Pressure

A = The area the weight is applied

W = The weight applied to the piston

The area the weight is applied, A = The area of the piston = π·D²/4

Where;

D = The diameter of the piston

∴ A = π × (0.004 m)²/4

When P = 3,00 bar, and A = π × (0.004 m)²/4, we have;

The weight applied, W = P × A

∴ W = 3,000 × π × (0.004 m)²/4 ≈ 3,769.9118 N

W ≈ 3,769.9118 N

W = m·g

Where;

m = The mass of weight

g = The acceleration due to gravity ≈ 9.81 m/s²

m = W/g

∴ m = 3,769.9118 N/(9.81 m/s²) ≈ 384.3 kg

The approximate mass of the weight required, m = 348.3 kg.

We started by Solving for the force and then the area of the piston, we then applied the formula for force using the constant for acceleration due to gravity and the mass was found to be 384.34 kg

Given Data

Pressure = 3000 bar

Diameter = 4mm

Let us convert bar to N/mm^2

1 bar = 0.1 N/mm^2

3000 bar = x N/mm^2

= 0.1*3000

= 300 N/mm^2

We know that pressure P = Force/Area

Let us find the area of the piston

Area = πd^2/4

Area = 3.142*4^2/4

Area = 3.142*16/4

Area = 50.272/4

Area = 12.568 mm^2

Let us find the force F

F = P*Area

F = 300*12.568

F = 3770.4 Newton

We know that Force = Mg

g = 9.81 m/s^2

Hence, m = F/g

m = 3770.4/9.81

m = 384.34 kg

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From Q = mcΔT, we can rearrange the equation to solve for mass, m = Q/cΔT. The specific heat capacity, c, of solid gold is 0.129 J/g °C. I'm assuming that the energy is given in joules, as it's not specified in the question as written.

m = Q/cΔT = (35.73 J)/(0.129 J/g °C)(40.85 °C - 0.85°C)

m = 6.92 g of gold was present  

The heat of the substance depends on the mass, specific heat, and temperature change of the system. The mass of gold that was present was, 6.92 g.

Mass of the substance in the thermodynamic system is the ratio of the heat to the product of the specific heat and the temperature change. It is given as,

[tex]\rm m = \rm \dfrac{Q}{c \Delta T}[/tex]

Given,

Heat (Q) = 35.73 J

Specific heat (c) = 0.129 J/g °C

Temperature change = 40 degrees celsius

Mass of gold is calculated as:

35.73 ÷ (0.129) (40) = 6.92 gm

Therefore, 6.92 gms of gold is present.

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Answer:

1.27atm is the pressure of the gas

Explanation:

Using combined gas law, we can find the pressure of a gas with the moles, temperature and volume of the gas. The formula is:

PV = nRT

P = nRT / V

Where P is pressure in atm

n are the moles of the gas: 4.6 moles

R is gas constant: 0.082tamL/molK

T is absolute temperature: 325K

V is volume: 96.8L

Replacing:

P = 4.6mol*0.082atmL/molK*325K / 96.8L

P = 1.27atm is the pressure of the gas

Answer:

Explanation:

Both the Arctic (North Pole) and the Antarctic (South Pole) are cold because they don't get any direct sunlight. The Sun is always low on the horizon, even in the middle of summer. In winter, the Sun is so far below the horizon that it doesn't come up at all for months at a time.

Answer:

The tilt of the Earth towards the Sun changes throughout the year.

Explanation

Answer:

220.9g of water are required

Explanation:

The molar enthalpy of vaporization is defined as the heat released when 1 mole of water changes from liquid to gas.

For water, 1 mole releases 40.79kJ. To release 500kJ are necessaries:

500kJ * (1mol / 40.79kJ) = 12.26 moles are necessaries

To convert moles to grams we must use the molar mass (H2O = 18.02g/mol):

12.26 moles * (18.02g / 1 mol) =

Answer:

C21H2802

Explanation:

C=12g/mol

H=1g/mol

O=16g/mol

Part (C) of compound-80.18%

(0.8018 x 312)/12=21

Part (H) of compound-8.97%

(0.897 x 312)/1=28

Part (O) of compund-10.3%

(0.103 x 312)/16 = 2

Therefore the emp. formula is C12H28O2

Answer:

the answer is 0 amu I hope it helps

Answer:

[tex]\boxed {\boxed {\sf 4038.48 \ Joules}}[/tex]

Explanation:

Since we are given the mass, specific heat, and change in temperature, we should use this formula for heat:

[tex]q=mc\Delta T[/tex]

The substance's mass is 450.0 grams, the specific heat is 1.264 J/g°C, and the  change in temperature is 7.1 °C.

[tex]m= 450.0 \ g \\c= 1.264 \ J/g \textdegree C\\\Delta T= 7.1 \ \textdegree C[/tex]

Substitute the values into the formula.

[tex]q= (450.0 \ g)(1.264 \ J/g \textdegree C)(7.1 \ \textdegree C)[/tex]

Multiply the first 2 values together. The grams will cancel out.

[tex]q= 568.8 \ J/ \textdegree C (7.1 \ \textdegree C)[/tex]

Multiply again. This time, the degrees Celsius cancel out.

[tex]q= 4038.48 \ J[/tex]

4038.48 Joules of heat energy are released.

Answer:

1 respuesta. fórmula empírica = CH2

Explanation:

Translatation: 1 Answer. empirical formula = CH2

Answer:

Explanation:  CH3COOH(aq) + H2O(l) ↔ CH3COO-(aq) + H3O+(aq) acid base ... sulfuric acid can react with either OH- or. H.

Answer:

Without the sun's energy, biological life would not be able to exist to decompose. Many microbes and fungi do their best work out of direct sunlight.

In an ecosystem, microbes make use of solar energy to decompose dead plant and animals.

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.There are different types of ecosystems present.

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A full Moon chances roughly every 29.5 days, so it may be possible the next full moon likely to appear in the night sky of Earth on July 29, hence the option B is correct.

The lunar phase during which the Moon is completely lit from Earth's viewpoint is known as the full moon.

When Earth is situated halfway between the Sun and the Moon, this happens. This indicates that the near side of the moon, which faces Earth, is fully illuminated by the sun and appears as a roughly round disc.

A full Moon chances roughly every 29.5 days, so it may be possible the next full moon likely to appear in the night sky on July 29.

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Answer: c

Explanation:

Answer:

the volume that the gas occupy at 7.47 atm is  0.1564 liters

Explanation:

The computation of the volume that the gas occupy at 7.47 atm is shown below:

As we know that

P1V1 = P2V2

Now

V2 = P1V1 ÷ P2

= 2.05 atm × 0.570 liters ÷ 7.47 atm

= 0.1564 liters

Hence, the volume that the gas occupy at 7.47 atm is  0.1564 liters

So the same would be considered and relevant

Answer:

beaner

Explanation:

Answer:

x= 1 /5 y+ 4 /5

Explanation:

Let's solve for x.

10x−2y=8

Step 1: Add 2y to both sides.

10x−2y+2y=8+2y

10x=2y+8

Step 2: Divide both sides by 10.

10x /10 = 2y+8 /10 x= 1 /5 y+ 4 /5

1 mole is equal to 1 moles CaCO3, or 100.0869 grams.

A mole is just a measuring scale. In reality, it's one of the International System of Units' seven foundation units (SI). When already-existing units are insufficient, new ones are created.

The mole is a SI unit that is used to quantify any quantity of a substance. The word "mole" is shortened to "mol".

A mole consists of precisely 6.022140761023 particles. The "particles" could be anything, from tiny things like electrons or atoms to enormous things like stars or elephants.

Therefore, 1 mole is equal to 1 moles CaCO3, or 100.0869 grams.

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Answer: Adiabatic process is a process in which heat is constant

Explanation:

The processes in which temperature remains constant is called isothermal process.

The process in which Volume remains constant is called isochoric process.  

The process in which pressure remains constant is called isobaric process.

 The process in which no heat is gained or lost by the system, Hence heat remains constant is called as adiabatic process.

Thus option d) heat is correct

Answer:

A.

Explanation:

Answer:

Option D, 116 g of NaNO3

Explanation:

An unsaturated solution is the one in which the amount of salt dissolved in more than the maximum amount of salt that can be dissolved in it.

At 50 degree Celsius, 37 grams of salt can be dissolved in 100 ml of water. Hence, 116 gram of salt is the correct answer

Answer:

5. Amplitude.

6. 344.8 meters/second

Explanation:

5. The energy is proportional to the amplitude is all I remember. Sorry :/ Been a long time since I took these classes.

6. Traveling to the wall & back is 200m

100 + 100 = 200m total traveled

The time is 0.58s so, we can use the speed formula to solve [ s = d/t ] where s = speed, d = distance, and t = time.

s = 200/0.58

s = 344.82758

I don’t know if they’ll have you round, but I would say the speed of the sound is 344.8 m/s.

Answer:

0.718L of 0.81M HCl are required

Explanation:

Based on the reaction:

Cd(s)+2HCI(aq) → H2(g)+CdCl2(aq)

1 mol of Cd reacts with 2 moles of HCl

To solve this question we must, as first, find the moles of Cd. With the moles of Cd we can find the moles of HCl needed to react completely with the Cd. With the moles and the molarity we can find the volume:

Moles Cd -Molar mass: 112.411g/mol-:

32.71g * (1mol / 112.411g) = 0.2910 moles Cd

Moles HCl:

0.2910 moles Cd * (2 moles HCl / 1mol Cd) =

0.5820 moles HCl

Volume:

0.5820 moles HCl * (1L / 0.81moles) =

Answer: The density will decrease

Explanation: Heating a substance causes molecules to speed up and spread slightly further apart, occupying a larger volume that results in a decrease in density.