All categories

3 years ago

Please help me!Will give the brainliest!Please answer correctly.Really urgent!!

Chemistry

1 answer:

Nostrana [21]3 years ago

3 0

Explanation:

1,a: I) group 2 = strontium

ii) chlorine

iii) nitrogen

B) i) strontium outer shell=2

ii)nitrogen:outer shell=5

iii) chlorine=7

C)metal

strontium

nickel

molybdenum

cesium

tin

non metal:..

chlorine

nitrogen

neon

You might be interested in

Calculate the energy, in joules, required to ionize a hydrogen atom when its electron is initially in the n =2 energy level. The

qaws [65]

Answer:

$E_{ionization}=5.45\times 10^{-19}\ J$

Explanation:

$E_n=-2.18\times 10^{-18}\times \frac{1}{n^2}\ Joules$

For transitions:

$Energy\ Difference,\ \Delta E= E_f-E_i =-2.18\times 10^{-18}(\frac{1}{n_f^2}-\frac{1}{n_i^2})\ J=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{n_i^2} - \dfrac{1}{n_f^2})\ J$

So, $n_i=2$ and $n_f=\infty$ (As the hydrogen has to ionize)

Thus,

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2} - \dfrac{1}{{\infty}^2})\ J$

$\Delta E=2.18\times 10^{-18}(\frac{1}{2^2})\ J$

$E_{ionization}=5.45\times 10^{-19}\ J$

4 0

3 years ago

Which of these sentences describes a benefit of fracking?

bagirrra123 [75]

Answer is: A. Fracking reduces U.S. dependency on oil and gas from other countries..
Other answers are not bad side of fracking.
Fracking is technique in which rock is fractured by a pressurized liquid and is used in to create cracks in the rock formations through which natural gas, petroleum will flow more freely.

7 0

3 years ago

Read 2 more answers

A 25.0g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is dropped into an insulated container containin

Angelina_Jolie [31]

Answer:

The equilibrium temperature of water is 25.6 °C

Explanation:

Step 1: Data given

Mass of the sample of brass = 25.0 grams

The specific heat capacity = 0.375 J/g°C

Mass of water = 250.0 grams

Temperature of water = 25.0 °C

The initial temperature of the brass is 96.7°C

Step 2: Calculate the equilibrium temperature

Heat lost = heat gained

Q(sample) = -Q(water)

Q = m*C* ΔT

m(sample)*c(sample)*ΔT(sample) = - m(water)*c(water)*ΔT(water)

⇒m(sample) = the mass of the sample of brass = 25.0 grams

⇒with c(sample) =The specific heat capacity = 0.375 J/g°C

⇒with ΔT = the change of temperature = T2 - T1 =T2 - 96.7 °C

⇒with m(water) = the mass of the water = 250.0 grams

⇒with c(water) = the specific heat capacity = 4.184 J/g°C

⇒with ΔT(water) = the change of temperature of water = T2 - T1 = T2 - 25.0°C

25.0 * 0.375 * (T2 - 96.7) = - 250.0 * 4.184 J/g°C * (T2 - 25.0°C)

9.375T2 - 906.56 = -1046T2 + 26150

9.375T2 + 1046T2 = 26150 + 906.56

1055.375T2 = 27056.26

T2 = 25.6 °C

The equilibrium temperature of water is 25.6 °C

4 0

3 years ago

what does ice cream melt on a hot day which type of thermal energy transfer does this melting represents

Rzqust [24]

Because the coldness in the ice cream and the suns gamma rays are hitting the ice cream and then it will start to melt. and that is why ice cream melts.

6 0

3 years ago

Would fire extinguishers that produce Carbon Dioxide (CO) gas be more effective in

yarga [219]

Answer:

They would be more efficient in ground fires since carbon dioxide is much greater in mass then oxygen, so its affected by gravity .

Explanation:

7 0

3 years ago

Please help me!Will give the brainliest!Please answer correctly.Really urgent!!​

Please help me!Will give the brainliest!Please answer correctly.Really urgent!!