At least, that's what Bohr<span> decided, and that's why he proposed the </span>existence<span> of the</span>atomic<span> energy level. </span>According<span> to </span>Bohr<span>, the electrons in an </span>atom<span> were only allowed to </span>exist<span> at certain energy levels</span>
The gradient is the slope of a linear equation, represented in the simplest form as y = mx + b. In Earth Science, the gradient is usually used to measure how steep certain changes in elevation are.
In order to find the gradient in a topographical setting, one must know two things: the elevation of two points and the distance between the two points. Once these values are known, the gradient can be found by dividing the change in field value, or the change in elevation, by the distance. The higher the gradient value is, the steeper the slope is.
Answer:
The elements are in the same column/group IIA.
See the explanation below, please.
Explanation:
The elements Calcium, Strontium, Beryllium, Magnesium, Barium and Radio, belong to the group of alkaline earth metals located in group IIA of the periodic table, they require 2 electrons to complete their octet (they have 2 valence electrons). reagents than alkali metals.
Answer:
B. flourine
Flourine is the 9th element in the periodic table
Answer:
Explanation:1.8
×
10
24
water molecules.
Explanation:
There are
6.022
×
10
23
molecules in a mole.
There are
18.01528
grams of water per mole of water.
These can be figured out using the concept of moles and molecular weight. I have attached a video that provides a good explanation.
Explanation of moles and molecular weight
Now you have all the information needed to solve the problem.
You start out with 54 grams of water. You want to convert that into molecules, but how can you do that? You can't go directly from grams to molecules because there is no easy unit conversion. However, you can go from grams to moles using
18.01528
grams of water per mole of water.
From there, you can go from moles to molecules using
6.022
×
10
23
molecules in a mole.
A T chart is useful for this kind of problem.
54 g H
2
O
×
1 mol H
2
O
18.0152 g H
2
O
×
6.022
×
10
23
molecules
1 mol H
2
O
54
g H
2
O
×
1 mol H
2
O
18.0152
g H
2
O
×
6.022
×
10
23
molecules
1 mol H
2
O
Notice when you apply this T chart, the units cancel out, leaving molecules in the final answer, which is the correct units.
Now actually multiply everything out
54
×
6.022
×
10
23
18.0152
=
1.805
×
10
24
You are left with
1.8
×
10
24
water molecules (rounded to two sig figs).
