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3 years ago

Problem

Chemistry

1 answer:

postnew [5]3 years ago

4 0

Answer:

C) Potassium, K, and calcium, Ca

Explanation:

Given pair of elements:

Ni and Cu

Potassium and Ca

Nitrogen and oxygen

Solution:

We know that number of protons and number of electrons are always equal and number of electron or number of proton is called atomic number.

Number of protons given elements:

Ni number of protons = 28

Copper number of protons = 29

Combine number of protons = 57

K number of protons = 19

Ca number of protons = 20

Combine number of protons = 39

Ni number of protons = 7

O number of protons = 8

Combine number of protons = 15

Thus, option C is correct.

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How many electrons does uranium have

lora16 [44]

Answer:

Explanation:

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3 years ago

Read 2 more answers

The electron configuration of a neutral atom is 1s22s22p63s2. Write a complete set of quantum numbers for each of the electrons.

Pavlova-9 [17]

Answer:

The four quantum number for each electron will be:

$1s^{2}$

$n=1;l=0;m=0;s=+\frac{1}{2}/-\frac{1}{2}$

$2s^{2}$

$n=2;l=0;m=0;s=+\frac{1}{2}/-\frac{1}{2}$

$2p^{6}$

$n=1;l=1;\\m=+1,0.-1 \\s=+\frac{1}{2}/-\frac{1}{2}$

$3s^{2}$

$n=3;l=0;m=0;s=+\frac{1}{2}/-\frac{1}{2}$

Explanation:

As the element is neutral, the number of protons will be equal to number of electrons which will be the atomic number of the element.

Number of electrons =12

Atomic number = 12

Element : Magnesium

The principal shell is represented by "n"

i) For "s" subshell the value of l =0 (azimuthal quantum number) thus m (magnetic quantum number)= 0

The two electrons in s subshell will have either plus half or minus half spin quantum number

ii) for "p" subshell the value for l =1

thus m = 0 or +1 or -1

The two electrons in each orbital will have either plus half or minus half spin quantum number

8 0

2 years ago

What is the daughter nucleus (nuclide) produced when 227th undergoes alpha decay?

Elina [12.6K]

Answer: -

²²³Ra is the daughter nuclide produced when ²²⁷Th undergoes alpha decay

Explanation: -

When alpha decay occurs, the mass number of the parent decreases by 4 and the atomic number decreases by 2.

Mass number of ²²⁷Th =227

Atomic number of ²²⁷Th = 90

Mass number of daughter = 227 - 4 = 223

Atomic number of daughter = 90 - 2 = 88

88 is the atomic number of Ra Radium.

Thus the daughter is ²²³Ra

6 0

3 years ago

Do you think there should be greater restrictions on who can buy explosives or accelerants? Why or why not?

fgiga [73]

In my opinion yes, as of now, almost anyone could get there hands on lets say an explosive. Have you heard of dynamite fishing? It is illegal, but it is still done once people have access to dynamite, then what ends up happening not only do marine wildlife get killed but it pollutes the water and lessens the chance of the natural cycle of life. Also there are several other factors, firstly, what will you do with an explosive once you get your hands on it? Perhaps you could just use an explosive for fun/personal entertainment...that isn't right and it could harm people. So, to conclude the harder it is for people to access explosives or even acclerants the better...and to add this can be possible by making people get like some sort of licence to use them, and let them be trained in certain conditions so that there is no regrets once they have access to them. I know my idea sounds far fetched but its a thought!

4 0

3 years ago

Read that From picture and tell me the answer please

Dafna11 [192]

Answer:

1g Hydrogen

Explanation:

<h3>Getting to the equation:</h3>

Calcium in water reacts vigorously to give a cloudy white Precipitate (compound) called Calcium hydroxide alongwith the evolution of Hydrogen gas.

$\boxed{ \mathsf{Ca + H_2O \rightarrow Ca(OH)_2 + H_2}}$

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Balancing the equation: </h3>

This reaction is not in it's balanced form! The number of atoms of Hydrogen on the left is 2 while that on the right is 4,I.e.,they're not equal.

Adding a 2 in front of H2O solves the problem by making the number of atoms of each element on both the sides equal.

$\mathsf{Ca +2 H_2O \rightarrow Ca(OH)_2 + H_2}$

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Observations:</h3>

Looking into the equation more carefully, we see:

1 atom of Calcium reacts with 2 molecules of water to give 1 molecule of Calcium Hydroxide alongwith 1 molecule of Hydrogen gas.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Gram atomic and molecular masses </h3>

Mass of one atom of Calcium = it's gram atomic mass

= 40 g

Mass of one "molecule" of Hydrogen

= it's Gram molecular mass

= gram mass of one atom × number of atoms in one molecule

= 1 × 2

= 2 g

So,

according to our observation:

One atoms of Calcium gives one molecule of Hydrogen (during the particular reaction)

=> 40g of Calcium gives = 2g of Hydrogen

•°• 1 g of Calcium gives = $\frac{2}{40}$

= $\frac{1}{20}$ g Hydrogen

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

<h3>Answer:</h3>

We're provided with 20g of Calcium,

=> 20g of Calcium gives = 20 × $\frac{1}{20}$ g H2

= 1 g H2

_______________

Hope this helps!

6 0

2 years ago