How many half-lives are required for three-fourths of the nuclei of an isotope in a sample to decay?

List all orbitals from 1s through 5s according to increasing energy for multielectron atoms. Rank orbitals from smallest to larg

Paha777 [63]

Answer:

The given list of orbitals can be ranked as follow:

1s 2s 2p 3s 3p 4s 3d 4p 5s.

Explanation:

The given list of orbitals can be ranked as follow:

1s 2s 2p 3s 3p 4s 3d 4p 5s.

According to the Aufbau principal in ground state of elements electron first occupy the lower energy level then fill the higher energy levels. We know that there four subshells s, p, d and f. The maximum number of electrons in these subshells can be calculated by following formula:

2 (2l +1 )

and l = 0,1,2,3,....

maximum numbers of electrons in s subshell are,

l=0

2 ( 2(0) + 1)

2

so maximum electrons in s subshell are 2.

maximum numbers of electrons in p subshell are,

l = 1

2 ( 2(1) + 1)

2( 2 + 1

6

so maximum electrons in p subshell are 6.

maximum numbers of electrons in d subshell are,

l = 2

2 ( 2(2) + 1)

2( 4 + 1)

10

so maximum electrons in d subshell are 10.

maximum numbers of electrons in f subshell are,

l = 3

2 ( 2(3) + 1)

2( 6 + 1)

14

so maximum electrons in f subshell are 14.

Electron first fill 1s subshell then 2s subshell and in this way they goes to higher energy levels.

3 0

2 years ago

There are two steps in the extraction of copper metal from chalcocite, a copper ore. In the first step, copper(I) sulfide and ox

Nastasia [14]

Answer:

The net chemical equation is:

$2Cu_2S + 3O_2 + 2C -> 2SO_2 + 2CO + 4Cu$

Explanation:

Condictions for extraction of copper metal allow the reaction ocurrs.

First step yield 2 moles of $Cu_2O$ , that later reacts with C, to poduce the copper metal.

Necessarily, reactions has to be balanced to know the proportion of each element.

In the first step oxygen (O2) replace sulfur (S), yielding sulfur dioxide and copper(I) oxide:

$2Cu_2S + 3O_2 -> 2Cu_2O + 2SO_2\\$

Next, copper(I) oxide reacts with carbon (C), yielding copper (Cu) and carbon monoxide:

$Cu_2O + C -> 2Cu + CO$

At the end, to complete the net chemical reaction, it is necessary multiply second step for 2, since it is obtained two moles of $Cu_2O$ from the first step. Then, we can sum both steps, reminding that species present in both terms are canceled.

$2Cu_2S + 3O_2 -> 2Cu_2O + 2SO_2\\2Cu_2O + 2C -> 4Cu + 2CO\\2Cu_2S+ 3O_2 + 2C -> 2SO_2 + 2CO + 4Cu$

3 0

2 years ago

PLEASE HELP ILL GIVE U BRAINLIEST<br> What's something you learned about the periodic table

valina [46]

Answer:

The periodic table of elements puts all the known elements into groups with similar properties. This makes it an important tool for chemists, nanotechnologists, and other scientists. If you get to understand the periodic table and learn to use it, you'll be able to predict how chemicals will behave.

7 0

2 years ago

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Redo the experiment by clicking on Reset Experiment. Add Ca(NO3)2 to 40 g of Na2CO3 and determine at what point the masses of th

Radda [10]

Answer : The mass of $Ca(NO_3)_2$ added must be, 61.9 grams