Answer:
2.5 m/s²
Explanation:
a = ∆v/∆t = (15 m/s)/(6 s) = (15/6) m/s² = 2.5 m/s²
Answer : The number of molecules of A needed to make 5000 molecules of AB will be, 5000
Explanation :
Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.
The given balanced chemical reaction is,

As per question, molecule B is an excess reagent because it had enough molecule to make 5000 molecules of AB. So, molecule A is limiting reagent.
From the balanced reaction, we conclude that
As, 1 molecule of AB produced from 1 molecule of A
So, 5000 molecule of AB produced from 5000 molecule of A
Hence, the number of molecules of A needed to make 5000 molecules of AB will be, 5000
The correct answer is I disagree. Elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds.
Elements are pure substances but these elements also make other things such as water. The water molecule is made of two elements called oxygen and Hydrogen. Now water itself is a pure substance as it is chemically bonded hydrogen and Oxygen but it is composed of more than one element
Oldest to youngest *Precambrian Era*Paleozoic *Mesozoic*Cenozoic
<span>2700 Joules
The important value here is how high the escalator moved you. The actual length doesn't matter. All it affects is how fast the work is performed upon you. So the escalator lifted 64 kg against gravity for 4.3m. So:
4.3 m * 9.8 m/s^2 * 64 kg = 2696.96 kg*m^2/s^2 = 2696.96 Joules
Rounding to 2 significant figures gives 2700 Joules</span>