Which of these pairs of elements have the same number of valence electrons?

Chemistry

2 answers:

TiliK225 [7]3 years ago

8 0

Berylium(Be) and calcium(Ca)

disa [49]3 years ago

4 0

Answer: Option (b) is the correct answer.

Explanation:

It is known that elements of same group tend to possess same number of valence electrons. As a result, they show same chemical properties.

Phosphorous (P) and chlorine (Cl) belongs to third period. Valence electrons of phosphorous are 5 and chlorine has 7 valence electrons.

Beryllium (Be) and Calcium (Ca) are group 2 elements and both of them have two valence electrons.

Helium (He) is a noble gas and it does not have any valence electrons.

Oxygen (O) has six valence electrons and carbon (C) has 4 valence electrons.

Therefore, we can conclude that berylium (Be) and calcium (Ca) is the pairs of elements have the same number of valence electrons.

You might be interested in

During an experiment, a student observes the formation of a precipitate. Why does this indicate that a chemical reaction is like

My name is Ann [436]

A. A solid forms, and there is a change of color.

8 0

3 years ago

Write a mechanism for the esterification of propanoic acid with 18O-labeled ethanol. Show clearly the fate of the 18O label. (b)

tatuchka [14]

Answer:

See explanation and images attached

Explanation:

a) In the mechanism for the acid catalysed esterification of propanoic acid using ethanol, we can see that the first step is the protonation of the acid followed by nucleophillic attack of the alcohol. Loss of water and consequent deprotonation regenerates the acid catalyst. We can see the fate of the 18O labelled ethanol in the mechanism shown.

b) In the second mechanism, an unnamed ester is hydrolysed using an acid catalyst. The attack of the acid and subsequent nucleophillic attack of water labelled with 18O leads to the incorporation of this 18O into the product acid as shown in the mechanism attached to this answer.

5 0

3 years ago

What volume would 3.01•1023 molecules of oxygen gas occupy at STP?

Sliva [168]

First, find moles of oxygen gas: (3.01 x10^23 molec.)/(6.02 x10^23) =0.5mol O2

Second, multiply moles by the standard molar volume of a gas at STP:(0.5mol)(22.4L) = 11.2L O2

6 0

3 years ago

Why doesnt science offer conclusive proof of phenomena

Rashid [163]

Evidence could be gathered in the future that contradicts original theories. <span>Phenomena cannot be proven by conclusive evidence in science because, as of now, the evidence isn't conclusive. It is speculation. Just as a phenomena cannot be proven, it also cannot be disproven. </span>

3 0

3 years ago

Which environment would you most likely have rich fertile soil

eimsori [14]

The environment where rich,fertile soil would most likely be is a flood plain.

Hope this helps!
Can u plz mark me as brainliest? I really need it!

7 0

3 years ago