Answer:
<h3>The answer is 0.03 moles</h3>
Explanation:
To find the number of moles given the number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
N = 2 × 10²² molecules of water
We have
We have the final answer as
<h3>0.03 moles</h3>
Hope this helps you
Answer: See below
Explanation: a. The mass of an element is composed of:
protons: 1 amu each
neutrons: 1 amu each
electrons: 0 amu each
Only the protons and neutrons are counted in the atomic mass of an element
b. Electrons are assigned a mass of 0. They do have a mass, but it is exceedingly small compared to the protons and neutrons, so they are left out of the calculation of an element's mass.
c. An element becomes unstable if the neutrons exceed the protons by a certain ratio, dependent on the element.
Answer:
The answer to your question is below
Explanation:
An endothermic reaction absorbs heat to proceed.
An exothermic reaction releases heat to proceed.
A. When a certain amount of potassium nitrate is dissolved in water, the water temperature drops from 23°C to 18°C. This is an example of an endothermic reaction because of the temperature diminishes.
B. Jack cooks himself a steak. This is an endothermic reaction because the steak does not cook itself it needs heat to be cooked.
C. When cold water is mixed with sulphuric acid, the mixture can rapidly reach the boiling point of water. This is an exothermic reaction because the temperature of water increases, which means that energy is been released.
D. A flare burns up slowly. I think it is an endothermic reaction because it was supply energy to proceed.