What important information did Ernest Rutherford discover about the atom?

What isotope name has a mass number of 201

Svetlanka [38]

Answer:

Thallium is an isotope name that has a mass number of 201

3 0

4 years ago

If Kp = 0.15, which statement is true of the reaction mixture before any reaction occurs?

Fiesta28 [93]

The given sentence is part of a longer question.

I found this question with the same sentence. So, I will help you using this question:

For the reaction N2O4(g) ⇄ 2NO2(g), a reaction mixture at a certain temperature initially contains both N2O4 and NO2 in their standard states (meaning they are gases with a pressure of 1 atm). If Kp = 0.15, which statement is true of the reaction mixture before any reaction occurs?

(a) Q = K; The reaction is at equilibrium.
(b) Q < K; The reaction will proceed to the right.
(c) Q > K; The reaction will proceed to the left.

The answer is the option (c) Q > K; The reaction will proceed to the left, since Qp = 1, and 1 > 0.15.
Explanation:

Kp is the equilibrium constant in term of the partial pressures of the gases.

Q is the reaction quotient. It is a measure of the progress of a chemical reaction.

The reaction quotient has the same form of the equilibrium constant but using the concentrations or partial pressures at any moment.

At equilibrium both Kp and Q are equal. Q = Kp

If Q < Kp then the reaction will go to the right (forward reaction) trying to reach the equilibrium,

If Q > Kp then the reaction will go to the left (reverse reaction) trying to reach the equilibrium.

Here, the state is that both pressures are 1 atm, so Q = (1)^2 / 1 = 1.

Since, Q = 1 and Kp = 0.15, Q > Kp and the reaction will proceed to the left.

6 0

4 years ago

A fossil you are radiometrically dating contains 4 micrograms of Uranium 235 and 4 micrograms of Lead 207. Uranium 235 decays to

Rzqust [24]

The rate at which radioactive substances disintegrate is a constant for a

given radioactive material.

The fossil is 710 million years old.

Reasons:

The half-life of a radioactive material is the time it takes half of the nucleus

of a radioactive material to disintegrate into other forms of materials

through the given off of energy and particles.

The half life of Uranium 235 = 710 million years

The product of the decay of Uranium 235 = Lead 207

The mass of Uranium 235 in the fossil = 4 micrograms

The mass of Lead 207 in the sample = 4 micrograms

Therefore, the mass of Lead 207 in the fossil is equal to the mass of

Uranium 235, therefore, a minimum of half of the Uranium 235 has

decomposed, which gives;

The time of decomposition of the Uranium 235 = 1 Half life = 710 million years

The age of the fossil = The time in which the Uranium has been

decomposing = The time of decomposition = 1 half life of Uranium 235 = 710

million years

The age of the fossil = 710 million years

Using the formula for half-life, we get;

$\displaystyle N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}}$

The fossil contains initially only Uranium 235 with a minimum mass of 4 mg

+ 4 mg = 8 mg, which gives;

N₀ = 8 mg

N(t) = The current mass of Uranium 235 = 4 mg

$\displaystyle t_{1/2}$ = 710 million years

$\displaystyle 4 = 8 \cdot \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

$\displaystyle \frac{4}{8} = \frac{1}{2} = \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

Therefore;

$\displaystyle \left( \frac{1}{2}\right)^1 = \left (\dfrac{1}{2} \right )^{\dfrac{t}{710}$

$\displaystyle 1 = {\dfrac{t}{710}$

t = 710

The age of the fossil, t = 710 million years

Learn more here:

brainly.com/question/20629992

3 0

2 years ago

Which of the following is the smallest volume? (2 points) 2500 mL

Virty [35]

So to put them all in the same units we have
2500 mL 
250 mL 
25mL 
2,500,000,000mL 

So the third one is the smallest

6 0

4 years ago

Read 2 more answers

A toddler peddling a tricycle applies a net force of 150N to the pedals. We will assume that 100% of this force is transferred t

vovangra [49]

Data:

F = 150 N

a = 5 m/s^2 (I corrected the units of acceleration)

m = ?

Formula: F = m*a (second Law of Newton).

Solution:

F = m*a => m = F / a

=> m = 150 N / 5 m/s^2 = 30 kg

Answer: the combined mass of the tricycle and toddler is 30 kg.

7 0

3 years ago