Pl help it’s for homwork

Why must each atom of an element always have the same number of protons?

Yuliya22 [10]

Atoms do not always contain the same number of electrons and protons, although this state is common. When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral. In contrast, when an atom loses or gains an electron (or the rarer case of losing or gaining a proton, which requires a nuclear reaction), the total charges add up to something other than zero.

8 0

4 years ago

Why is U-235 the most common nuclear fuel instead of the more abundant U-238? State a clear topic sentence and support it with e

GREYUIT [131]

<h3>Answer and explanation;</h3>

The isotope U-235 is an important common nuclear fuel because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be 'fissile' and use the expression 'nuclear fission'.
Uranium 238 on the other hand is not fissionable by thermal neutrons, but it can undergo fission from fast or high energy neutrons. Hence it is not fissile, but it is fissionable.
In a nuclear power station fissioning of uranium atoms replaces the burning of coal or gas. Heat created by splitting the U-235 atoms is then used to make steam which spins a turbine to drive a generator, producing electricity.

3 0

3 years ago

Identify the element: 6 energy level, metallic, 82 election

Lady bird [3.3K]

Answer:-

Name of element = Lead

Symbol ♾ of Lead = Pb

Atomic no. = 82

Atomic mass = 207.2 amu

No. of protons = 82

No. of electrons = 82

Yes, lead(Pb) is a metallic element and certainly it has 6 electron shells which means 6 energy level.

If you find anything unclear you can ask me...

6 0

3 years ago

Question 11 (3 points)

Ugo [173]

Answer:

The outer core of the earth is liquid.

Explanation:

Seismic waves travel through the Earth at different speeds and are reflected and refracted diffracted differently as they encounter layers of different densities.

By analyzing these waves, they have concluded that there is an inner core of solid iron surrounded by a liquid outer core consisting of nickel and iron.

A is wrong. The Earth consists of several layers

C is wrong. Seafloor spreading is caused by the movement of tectonic plates away from each other.

D is wrong. The mantle is mostly solid rock.

4 0

3 years ago

An enclosed vessel contains 2.5g of 9b nitrogen and 13.3g of chlorine at s.T.P. Of What will be the partial pressure of the Il n

kow [346]

Answer:

0.535 atm

Explanation:

Since the volume of the tank is constant, we use Gay- Lussac's law to find the pressure at 180°C.

So, P₁/T₁ = P₂/T₂ where P₁ = pressure at S.T.P = 1 atm, T₁ = temperature at S.T.P = 273.15 K, P₂ = pressure of gas at 180 °C and T₂ = 180 °C = 273.15 + 180 K = 453.15 K

So, P₁/T₁ = P₂/T₂

P₂ = P₁T₂/T₁

Substituting the values of the variables into the equation, we have

P₂ = P₁T₂/T₁

P₂ = 1 atm × 453.15 K/273.15 K

P₂ = 1 atm × 1.66

P₂ = 1.66 atm

We now need to find the total number of moles of each gas present

number of moles of nitrogen = mass of nitrogen, m/molar mass of nitrogen molecule M

n = m/M

m = 2.5 g and M = 2 × atomic mass of nitrogen (since it is diatomic) = 2 × 14 g/mol = 28 g/mol

So, n = 2.5 g/28 g/mol

n = 0.089 mol

number of moles of chlorine, n' = mass of chlorine, m'/molar mass of chlorine molecule M'

n' = m'/M'

m' = 13.3 g and M = 2 × atomic mass of chlorine (since it is diatomic) = 2 × 35.5 g/mol = 71 g/mol

So, n' = 13.3 g/71 g/mol

n' = 0.187 mol

So, the total number of moles of gas present is n" = n + n' = 0.089 mol + 0.187 mol = 0.276 mol

So, the partial pressure due to nitrogen gas, P = mole fraction of nitrogen × pressure of gas at 180 °C

P = n/n" × P₂

P = 0.089 mol/0.276 mol × 1.66 atm

P = 0.322 × 1.66 atm

P = 0.535 atm

8 0

3 years ago