Answer:
is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results
Answer:
Concentrated sulfuric acid is used as a catalyst, and has a dual role:
-Speeds up the reaction.
-Acts as a dehydrating agent, forcing the equilibrium to the right and resulting in a greater yield of ester.
Answer:
CaCl
2
Explanation:
As with all these problems, we assume a
100
⋅
g
of compound, and divide through by the ATOMIC masses of each component element:
Moles of calcium
=
36.1
⋅
g
40.08
⋅
g
⋅
mol
−
1
=
0.901
⋅
mol
.
Moles of chlorine
=
63.9
⋅
g
35.45
⋅
g
⋅
mol
−
1
=
1.802
mol
.
We divide each molar quantity through by the smallest molar quantity (that of calcium) to give an empirical formula of
CaCl
2
.
For ionic materials, we do not speak of the molecular formula, and the empirical formula is the formula we quote for reference.
I think the best answer for this question is the third option. Electrons form a cloud around the nucleus. According to modern physics, electrons are in constant motion around the nucleus and protons. Additionally, electrons, protons and neutrons are considered as hard particles.
I don't know much about this, but probably the reason why your teacher circled 300k is because of what's in the photo below. If you couldn't tell from the photo, its because 300k isn't negative. Anyway this is my guess, based on my limited knowledge.