Science 9- Bohr models worksheet

Uranium, an important component of both nuclear weapons and nuclearreactors, has two major isotopes, U-238, which has a half-lif

elixir [45]

Answer:

Hello your question is poorly written below is the well written question

Uranium, an important component of both nuclear weapons and nuclear reactors, has two major isotopes, U-238, which has a half-life of approximately 4.5 billion years, and U-235, which has a half-life of approximately 700 million years. Both were present in equal amounts at the time of the creation of the Earth, 4.5 billion years ago. How many years after the creation of the Earth had the amount of radiation from uranium decayed to half the amount present at the time of the creation of the Earth

Answer : 140 billion years

Explanation:

Given that :

U-238 h1/2 = 4.5 billion years

U-235 h1/2 = 700 million years

At the beginning both Isotopes where present in equal amount

Determine the T years before the amount of Uranium decays to Half

T = ? N'2 = N1 / 2

we know that N = No ( 1/2 )^h where h = time / half-life time

attached below is the detailed solution of the given problem

6 0

3 years ago

Ferris & Mona used the ORP sensor to titrate a ferrous ammonium sulfate solution, (NH4)2Fe(SO4)2 with KMnO4 titrant.

DIA [1.3K]

Answer:

The correct option is: A. 0.168 M

Explanation:

Chemical reaction involved:

5 Fe²⁺ (aq) + MnO₄⁻ (aq) + 8 H⁺ (aq) → 5 Fe³⁺ (aq) + Mn²⁺ (aq) + 4 H₂O

Given: For MnO₄⁻ solution-

Number of moles: n₁ = 1, Volume: V₁ = 20.2 mL, Concentration: M₁ = 0.0250 M;

For Fe²⁺ solution:

Number of moles: n₂ = 5, Volume: V₂ = 15 mL, Concentration: M₂ = ?M

To find out the concentration of Fe²⁺ solution (M₂), we use the equation:

$\frac{M_{1}\times V_{1}}{n_{1}} = \frac{M_{2}\times V_{2}}{n_{2}}$

$\frac{0.0250 M\times 20.2 mL}{1} = \frac{M_{2}\times 15 mL}{5}$

$0.505 = M_{2}\times 3$

$M_{2} = \frac{0.505}{3} = 0.168M$

Therefore, the concentration or molarity of Fe²⁺ solution: M₂ = 0.168 M

8 0

4 years ago

I need chemistry help! How would I set up these problems?

Bond [772]

Answer: -

1) 8.33 minutes

2) 118.39 in/ s

180.43 m/min

10.83 km/ hr

Explanation: -

Speed of light = 3 x 10⁸ m/s

Distance of the earth from the sun= 93 million miles

We know 1 million = 1,000,000

Also 1 mile = 1609 m

Distance of the earth from the sun= 93 million miles

= 93,000,000 miles.

= 1.5 x $10^{11}$ m

Time taken = $\frac{Distance}{Speed}$

= $\frac{1.5 x [tex] 10^{11}$ m}{3 x 10⁸ m/s} [/tex]

= 500 s

= 500/ 60

= 8.33 minutes

2) Distance = 1 mile = 63360 inches

Time taken = 8.92 min

= 8.92 x 60

= 535.2 s

Speed = $\frac{distance}{time}$

= $\frac{63360 inches}{535.2 s}$

= 118.39 in/ s

Distance = 1 mile = 63360 inches = 63360 x 2.54 cm = 63360 x 2.54 x $10^{-2}$ m

Time taken = 8.92 min

Speed = $\frac{distance}{time}$

= $\frac{63360 x 2.54 x [tex] 10^{-2}$ m}{8.92 min} [/tex]

= 180.43 m/ min

1 m = 10⁻³ Km

1 min = 1/60 hour

1 m /min = 10⁻³ km/ $\frac{1}{60 hour}$

= 60/1000

=0.06 km/hr

180.43 m / min = 180 x 0.06 km / hr

= 10.93 km / hr

4 0

3 years ago

Balanced equation for the neutralization of these 2. HCl , Ca(OH)2

Ghella [55]

Balanced equation:

2 HCl + 1 Ca(OH)₂ = 1 CaCl₂ + 2 H₂O

hope this helps!

5 0

3 years ago

Read 2 more answers

What particles form the nucleus of an atoms?

melomori [17]

Answer:

Protons and neutrons

Explanation:

The particles to forms the nucleus of an atom are the protons and neutrons of the atoms.

These materials are located in the tiny nucleus and contributes the most mass of the atom.

Protons are the positively charged particles in an atom
Neutrons do not carry any charges.
Sum of the protons and neutrons gives the mass number of the atom.

7 0

3 years ago