Gravity pulls gas and dust together. A protostar forms as mass increases.
A national day is a day on which celebrations mark the nationhood of a nation or state. It may be the date of independence, of becoming a republic, or a significant date for a patron saint or a ruler (such as a birthday, accession, or removal). The national day is often a public holiday.
Answer:
Explanation:
Your strategy here will be to
use the chemical formula of carbon dioxide to find the number of molecules of
CO
2
that would contain that many atoms of oxygen
use Avogadro's constant to convert the number of molecules to moles of carbon dioxide
use the molar mass of carbon dioxide to convert the moles to grams
So, you know that one molecule of carbon dioxide contains
one atom of carbon,
1
×
C
two atoms of oxygen,
2
×
O
This means that the given number of atoms of oxygen would correspond to
4.8
⋅
10
22
atoms O
⋅
1 molecule CO
2
2
atoms O
=
2.4
⋅
10
22
molecules CO
2
Now, one mole of any molecular substance contains exactly
6.022
⋅
10
22
molecules of that substance -- this is known as Avogadro's constant.
In your case, the sample of carbon dioxide molecules contains
2.4
⋅
10
22
molecules CO
2
⋅
1 mole CO
2
6.022
⋅
10
23
molecules CO
2
=
0.03985 moles CO
2
Finally, carbon dioxide has a molar mass of
44.01 g mol
−
1
, which means that your sample will have a mass of
0.03985
moles CO
2
⋅
44.01 g
1
mole CO
2
=
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
∣
∣
a
a
1.8 g
a
a
∣
∣
−−−−−−−−−
The answer is rounded to two sig figs, the number of sig figs you have for the number of atoms of oxygen present in the sample.
On the off chance that the red blood cells are smaller than ordinary, this is called microcytic anemia. The significant reasons for this sort are low-level iron, anemia, thalassemia.
Answer:
8700
Explanation:
First, do the operations i<em>nside parentheses</em>.
102 900/12 = 8600 2 sfs because of 12
170/1.27 = 130 2 sfs because of trailing 0 in 170
===============
Now, do the addition.
8600
<u> + </u><u>13</u><u>0
</u>
8700
The answer has two significant figures because when adding, you must round your answer to the same "place" as the measurement with its last significant figure furthest to the left.
The last significant figure in 8600 (the 6, in the hundreds place) is further to the left than the last significant figure in 130 (the 3, in the tens place).
We round off to the nearest hundred and get the answer, 8700.
