Answer:
The gases will expand until a volume of Vf= 10812 cm^3
Explanation:
Since the gas mixture is expanding at constant pressure
and therefore
knowing that 1 torr=133,32 Pa
therefore
You can identify a mineral by its appearance and other properties. The color and luster describe the appearance of a mineral, and streak describes the color of the powdered mineral.
The % composition of each element is calculated as follows
= mass of the element/total mass x100
total mass= 73.5+4.2+72.3=150
% composition of C = 73.5/150 x100=49%
% composition of H= 4.2/150 x100= 2.8%
%composition of Cl= 72.3/150 x100= 48.2%
Answer:
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- <em>The halogens posses </em><u><em>seven </em></u><em>valence electrons</em>
Explanation:
- <em>Valence electrons </em>are the electrons in the outermost orbitals of the atoms, which are the orbitals with the highest main energy level (principal quantum number).
- Halogens are the elements of the group 17 of the periodic table: F, Cl, Br, I, At.
- You can tell the number of valence electrons of the representative elements from the number of the group to which they belong. For the representative elements, the number of valence electrons equal the unit digit of the group number.
This table summarizes it:
Group number number of valence electrons
1 1
2 2
13 3
14 4
15 5
16 6
17 7
18 8
- So, in conclusion, <em>the halogens possess 7 valence electrons.</em>
Answer:
1. Source of carbon
2. Removal of cuticle
Explanation:
You may have been doing a photosynthesis lab in a biology course.
1. NaHCO₃
The purpose of creating a sodium bicarbonate solution was to provide the carbon that the plant needs for photosynthesis.
2. Soap solution
The soap solution acted as a detergent. It removed some of the waxy, water-repelling cuticle from the leaf's surface and made it easier for the sodium carbonate solution to get inside.
