Who suggested the idea of continental drift and the existence of an original supercontinent? NEED HELP ASAP WILL MARK BRAINLIEST

An atom has the electron arrangement 2,8. What will it do to gain a full

777dan777 [17]

The answer is B) gain 8 electrons

8 0

3 years ago

If 8.00 g NH4NO3 is dissolved in 1000 g of water, the water decreases in temperature from 21.00 degrees Celsius to 20.39 degrees

telo118 [61]

Answer:

25.7 kJ/mol

Explanation:

There are two heats involved.

heat of solution of NH₄NO₃ + heat from water = 0

q₁ + q₂ = 0

n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃

∴ n = 0.100 mol NH₄NO₃

q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln

m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g

q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J

q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0

ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol

7 0

3 years ago

Arrange the elements in decreasing order of first ionization energy.

just olya [345]

Answer:

The decreasing order of first ionization energy: Se > Ge > In > Cs

The decreasing order of first ionization energy: x > y > z

Explanation:

Ionization energy refers to the energy needed to completely pull out an electron from the valence shell of a neutral gaseous atom.

First ionization energy is the energy involved in the removal of first valence electron.

In the periodic table, down the group, as atomic radius of elements increases, the ionization energy decreases

Whereas, across a period, as atomic radius of elements decreases, the ionization energy increases.

PART (A):

Position of the given elements in the periodic table:

Indium (In): Group 13, period 5

Germanium (Ge): Group 14, period 4

Selenium (Se): Group 16, period 4

Caesium (Cs): Group 1, period 6

Thus, the increasing order of atomic radius: Se < Ge < In < Cs

Therefore, the decreasing order of first ionization energy: Se > Ge > In > Cs

PART (B):

Given elements:

element x: radius = 110 pm

element y: radius = 199 pm

element z: radius = 257 pm

Thus, the increasing order of atomic radius: x < y < z

Therefore, the decreasing order of first ionization energy: x > y > z

5 0

3 years ago

What volume does 14 mol of gas occupy at STP? Round to the nearest hundredth.

Anna007 [38]

Answer:

The volume is 310 L

Explanation:

We use the ideal gas formula, with the constant R = 0.082 l atm / K mol. The STP conditions are 1 atm pressure and 273 K temperature. Solve for the formula, V (volume):

PV= nRT ---> V= (nRT)/P

V=( 14 mol x 0,082 l atm /K mol x 273 K)/ 1 atm

V= 313,404 L

4 0

3 years ago

100 PIONTS!!!! HELLLLPP MEEEE PLEASSSE ITS MY FINALLLLL AND ITS DUE TODAYYYYY

Dafna1 [17]

Answer:

The liquid Iodine may bubble as you boil it.

Explanation:

4 0

3 years ago

Read 2 more answers