The octet rule is that atoms must have 8 valence electrons to have an octet. Usually, when atoms have an octet, they tend not to bond with any other atoms because they are already stable and do not need to bond anymore.
Answer:
The fourth one down
Explanation:
It is the only setup in which the units of "cm" and "in" cancel correctly and give the desired units of "ft."
The second one down has the correct units but the wrong conversion factor for converting centimetres to inches.
Answer:
The correct answer is option B.
Explanation:
Endothermic reactions are defined as the reactions in which energy of products is more than the energy of the reactants. In these reactions, energy is absorbed by the system.
The total enthalpy of the reaction
comes out to be positive.
Exothermic reactions are defined as the reactions in which energy of reactants is more than the energy of the products. In these reactions, energy is released by the system.
The total enthalpy of the reaction
comes out to be negative.
On mixing of both solution we had observed that temperature of the resulting solution was lowered this is because the energy was absorbed during the chemical reaction.
D. acceleration
Explanation:
When an object's speed and direction are known, its acceleration can also be determined.
Acceleration is defined as the change in velocity of a body in motion with time.
Most times, velocity and speed can be changed if the direction a body is traveling is known.
Acceleration = 
The S.I unit of acceleration is always expressed as m/s²
Learn more:
Acceleration brainly.com/question/3820012
#learnwithBrainly
Answer:
548s = t
Explanation:
A first-order reaction has as general equation:
![ln \frac{[A]_t}{[A]_0} = -kt](https://tex.z-dn.net/?f=ln%20%5Cfrac%7B%5BA%5D_t%7D%7B%5BA%5D_0%7D%20%3D%20-kt)
Where
is the concentration of the reactant in the time t,
is the initial concentration of the reactant, k is rate constant and t is time. Replacing with values of the problem:

-1.65 = -3.00x10⁻³s⁻¹×t
<em>548s = t</em>
<em></em>
I hope it helps!