Which of the first four radioisotopes in the decay series has the longest half-life? Pa-234 Th-234 U-234 U-238

Answer: Electrons

Explanation:

Answer:

25cm³ = 0.025L of H2So4

Molarity of H2SO4 = 1moldm-³

Recall ... 1dm-³ = 1L

So the Molarity can also be 1mol/L

Mole = Molarity x volume in L

Mole of H2SO4 = 1mol/L x 0.025L

=0.025Moles of Sulphuric acid reacted.

From the equation of reaction

1mole of H2SO4 reacts to produce 1mole of Copper sulphate crystal

Since their Mole ratio is 1:1

It means that Since 0.025mole of H2SO4 reacted.... 0.025mole of CuSO4.5H2O would be produced

Nice.. OK

So we know the moles of CuSO4.5H2O produced

We can get the Mass

Recall

From

Mole=Mass/Molar Mass

Mass = Mole x Molar Mass

Molar Mass of CuSO4.5H2O = 64 + 32 + 16x4+ 5(2+16)

Mm= 250g/mol

Mass = 0.025mol x 250g/mol

= 6.25g of CuSO4.5H2O crystals Would be PRODUCED.

Answer: The partial pressure of nitrogen gas if the total pressure is 111.7 atm is 88.243 atm.

Explanation:

Given: Mole fraction of oxygen = 0.21

Total pressure = 111.7 atm

It is known that the sum of moles fractions is always equal to 1. So, mole fraction of nitrogen is calculated as follows.

Mole fraction of nitrogen + mole fraction of oxygen = 1

Mole fraction of nitrogen = 1 - mole fraction of oxygen

Mole fraction of nitrogen = 1 - 0.21

Mole fraction of nitrogen = 0.79

Now, formula used to calculate the partial pressure of nitrogen is as follows.

[tex]P_{N} = X_{N} \times P_{total}[/tex]

where,

[tex]P_{N}[/tex] = partial pressure of nitrogen

[tex]X_{N}[/tex] = mole fraction of nitrogen

[tex]P_{total}[/tex] = total pressure

Substitute the values into above formula as follows.

[tex]P_{N} = X_{N} \times P_{total}\\= 0.79 \times 111.7 atm\\= 88.243 atm[/tex]

Thus, we can conclude that the partial pressure of nitrogen gas if the total pressure is 111.7 atm is 88.243 atm.

Answer:

The correct answer is - neutrons.

Explanation:

Uranium has various isotopes found naturally that are three 238U, 235U, and 234U. Uranium has an atomic number of 92 which means there are 92 protons and 92 electrons in the atomic structure.

Isotopes have the same number of protons but a different number of neutrons that can vary from 141 to 146. U-238 has 146 neutrons in the nucleus, whereas 235 U has 143 neutrons.

The U- 238 has more neutrons than U- 235. Atomic mass is the sum total of the nucleons or protons and neutrons.

What are Isotopes?

They are the different variants of the same molecules which have the same number of protons but the different number of neutrons.

Atomic mass is the sum total of the nucleons or protons and neutrons. The atomic number of Uranium is 92, the rest of the mass comes from neutrons.

Therefore, the U- 238 has more neutrons than U- 235.

Learn more about Isotopes:

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Answer:

6.55 x 10^22 atoms K

Explanation:

Convert from grams to moles (using K molar mass)

K molar mass = 39.098 g/mol

4.25 g K x 1 mol K / 39.098 g K

[grams cancel out]

= 0.1087 mols K

Convert from moles to atoms (using Avogadro's number)

Avogadro's number = 6.0221 x 10^23

0.1087 mols K x 6.0221 x 10^23 atoms K / 1 mols K

[mols cancel out]

= 6.545987 x 10^22

[with proper significant digits.....]

= 6.55 x 10^22 atoms K

Answer:

= -592 (7+3)

= 592 ×10

= -5920

hope it helps u

Mark me brainless

Answer: I believe the answer is d)  the rock crumbles at an ocean ridges

Explanation:

Answer:

A. Yes

B. The new temperature of the gas is -116 °C

Note: The question is incomplete. The complete question is given below :

For many purposes we can treat butane C H10) as an ideal gas at temperatures above its boiling point of - 1. °C. Suppose the pressure on a 500 mL sample of butane gas at 41.0°C is cut in half. Iyes Is it possible to change the temperature of the butane at the same time such that the volume of the gas doesn't change? yes no If you answered yes, calculate the new temperature of the gas. Round your answer to the nearest °C.

Explanation:

A. According to the pressure law of gases,for a fixed mass of gas the pressure of a gas is directly proportional to its Kelvin temperature once the volume is kept constant. This means that a change in temperature can bring about a change in pressurein a gas at constant volume.

B. From the pressure law of gasese: P1/T1 = P2/T2

Where initial pressure = P1, final pressure = P2

Initial temperature = T1, final temperature = T2

For the butane gas;

P1 = P

P2 = P/2

T1 = 41°C = (273 + 41 ) K = 314 K

T2 = ?

From the equation, T2 = T1 × P2 / P1

T2 = 314 × P/2 /P

T2 = 157 K

T2 = (157 - 273) °C = -116 °C

Therefore, the new temperature of the gas is -116 °C

Answer:

Explanation:

Tenochtitlan was located on a swampy island in Lake Texcoco in what is today south central Mexico. The Aztecs were able to settle there because no one else wanted the land. At first, it wasn't a great place to start a city, but soon the Aztecs built up islands where they could grow crops. The water also worked as a natural defense against attacks from other cities.

Read more at: https://www.ducksters.com/history/aztec_empire/tenochtitlan.php

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The charge on a molecule with 14 electrons and 12 protons = -2

Although your question is vague a general answer is provided above

When the number of protons and the number of electrons in a molecule are equal to each other, the charge on the molecule will be neutral, this is because Electrons are negatively charged while protons are positively charged.

Therefore a molecule with 14 electrons and 12 protons will have a charge of

=  -14 + 12 = - 2

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Answer:

2969429th Ave

Explanation:

i dont know

Answer:

5250 grams or 5.25 kg of carbon monoxide and 375 grams of hydrogen are required to form 6 kg of methanol.

Explanation:

The balanced reaction:

CO (g) + 2 H₂ (g) -> CH₃OH (l)

By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:

Being the molar mass of each compound:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

Being 6 kg equivalent to 6000 grams (1 kg= 1000 grams), you can apply the following rules of three:

[tex]mass of carbon monoxide=\frac{6000 grams of methanol*28 grams of carbon monoxide}{32 grams of methanol}[/tex]

mass of carbon monoxide= 5250 grams= 5.25 kg

If by stoichiometry 32 grams of methanol are formed from 2 grams of hydrogen, 6000 grams of methanol are formed from how much mass of hydrogen?

[tex]mass of hydrogen=\frac{6000 grams of methanol*2 grams of hydrogen}{32 grams of methanol}[/tex]

mass of hydrogen= 375 grams

5250 grams or 5.25 kg of carbon monoxide and 375 grams of hydrogen are required to form 6 kg of methanol.

Answer:

7.41 × 10⁻⁵

Explanation:

Let's consider the basic dissociation reaction of trimethylamine (CH₃)N).

(CH₃)N + H₂O = (CH₃)NH⁺ + OH⁻

According to Brönsted-Lowry, in this reaction (CH₃)N is a base and (CH₃)NH⁺ is its conjugate acid. The pKb for (CH₃)N is 9.87. We can calculate the pKa of (CH₃)NH⁺ using the following expression.

pKa + pKb = 14

pKa = 14 - pKb = 14 - 9.87 = 4.13

Then, we can calculate the acid dissociation constant for (CH₃)NH⁺ using the following expression.

pKa = -log Ka

Ka = antilog - pKa = antilog -4.13 = 7.41 × 10⁻⁵

Geometric isomers have the same structural formulas but differ in the arrangement of groups at a single atom, at double bonds, or in rings. ... One of the optical isomers rotates the light in one direction, the other rotates the light in the opposite direction but by the same amount.

Answer:

39.2 g

Explanation:

First we convert 55.3 grams of Ni₂O₃ into moles of Ni₂O₃, using its molar mass:

Then we convert 0.334 moles of Ni₂O₃ into moles of Ni, using the stoichiometric coefficients of the balanced reaction:

Finally we calculate how much do 0.668 Ni moles weigh, using the molar mass of Ni :

Answer: It is :B:

Explanation: also sub to technoblade

Answer:b

Explanation:

Answer:

The formula for volume of a rectangle is length multiply by width multiply thus, 0.25 m multiply 6.1 m multiply by 4.9 m = 7.5m^3.

Explanation:

the least number of significant figures is 2 thus the final answer will have the same number of significant figures. 7.5m^3

For the first

H : O : H

Theres two bonds here

Each other are sigma

So 2Sigma bonds present

For the Second

I believe you wanted to write Ethyne....

In a triple bond... Theres 1sigma and 2 Pi bonds

Every single bond is a sigma bond

So

Counting all

we have

2Pi bonds and 3Sigma bonds

Answer:

B

Explanation:

conduction is the transfer of heat between objects that touch

Answer: A chemical equilibrium exists when the rate at which reactants form products is the same as the rate at which products form reactants.

Explanation:

When the concentration of both the reactants and products do not change with time then it means the chemical reaction has reached to a state of chemical equilibrium.

For example, [tex]CO(g) + Cl_{2}(g) \rightleftharpoons COCl_{2}(g)[/tex]

Therefore, we can conclude that a chemical equilibrium exists when the rate at which reactants form products is the same as the rate at which products form reactants.

Answer:

[tex]V_2=10L[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to calculate the required new volume by using the Charles' law as a directly proportional relationship between temperature and volume:

[tex]\frac{V_2}{T_2} =\frac{V_1}{T_1}[/tex]

In such a way, we solve for V2 and plug in V1, T1 and T2 to obtain:

[tex]V_2=\frac{V_1T_2}{T_1}\\\\V_2=\frac{5.0L*600K}{300K}\\\\V_2=10L[/tex]

Regards!

Answer:

Hydroxylamine and pyridine

Explanation:

Just did it

Answer:

Following are the solution to the given question:

Explanation:

For question 1:

For question 2:

Answer:

Option 3 and 4

Explanation:

In an endothermic reaction, the potential energy of the system increase. The potential energy of the reactant is less as compared to the potential energy of the products and hence additional energy is required to produce products.

The potential energy of the reactants depend on their chemical state and not the physical state. Hence, option 2 is not correct. Also, the number of reactant do not make any significant impact on the determination of potential energy of reactants. Thus, option 1 is also incorrect

The one on the top left corner is condensation. The one below that is evaporation. The one below that in the water is accumulation. The one next to accumulation is ground flow. The one on the trees is transpiration. The one above transpiration is surface flow. The one above surface flow is precipitation and above precipitation it’s condensation. Lmk if you were able to get that.

Answer:

Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks).

Explanation:

Answer:

Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks).

The colors are produced by heating metal salts, such as calcium chloride or sodium nitrate, that emit characteristic colors. ... Barium – Barium is used to create green colors in fireworks, and it can also help stabilize other volatile elements. Calcium – Calcium is used to deepen firework colors