The octet rule states that in chemical compounds atoms tend to have

In chemical compounds, atoms tends to have the electron configuration of a noble gas.

Explanation:

The noble gases are unreactive because of their electron configurations. This noble gas neon has the electron configuration of 1s22s22p6 . It has a full outer shell and cannot incorporate any more electrons into the valence shell.

The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons and thus the electron configuration of a noble gas. An exception to an octet of electrons is in the case of the first noble gas, helium, which only has two valence electrons.

The octet rule states that atoms tend to form compounds in ways that give them eight valence electrons just like the electron configuration or valency of a noble gas

Explanation: The Octet rule tend to show that Atoms prefer to fill up the eight valence electron in order to make their shell complete to achieve the valency of the Noble gases.

Helium is an exception to the Octet rule as it only has two valence electrons in its outermost shell.

Sharing of electrons which is one of the characteristics of a Octet rule in trying to achieve covalent bonding makes the compound formed more stable.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s