I found the rest of the exercise on the internet and these are the options.
"-Undifferentiated vertebrae throughout the body.
-One neck vertebra allowing up and down movement.
-Many neck vertebrae that allow for greater mobility.
<span>-Two neck vertebrae allowing up and down and sideways movement."
The correct answer would be the third. - "</span>Many neck vertebrae that allow for greater mobility." The <span>present-day organism with four limbs has a neck with several vertebrae that allow movements of rotation (mostly because of only two vertebrae at the top of the neck), and side way movements, as well as back and forth movements.</span>
An exothermic reaction is a type of chemical reaction in which energy is released to the environment in form of heat or light. Endothermic reaction in the other hand is a chemical reaction where energy is taken from the surroundings and thus the surroundings end up with less energy than they started with. In this case; the above reaction is an Exothermic reaction (heat is being released to the surroundings).
Answer:
Water has the greatest ΔEN
ΔEN H₂O → 3.4 - 2.1 = 1.3 Option D.
Explanation:
We should find the Electronegativity data in the Periodic table for all the elements:
C : 2.6
O: 3.4
H: 2.1
S: 2.6
N: 3.0
a. ΔEN CO₂ → 3.4 - 2.6 = 0.4
b. ΔEN H₂S → 2.6 - 2.1 = 0.5
c. ΔEN NH₃ → 3 - 2.1= 0.9
d. ΔEN H₂O → 3.4 - 2.1 = 1.3
Answer:
A) 0.20 cm³
B) 49.7 m²
C) 99.99%
D) 17.7 mg
Explanation:
A) The density of a material represents the mass that it occupies in a "piece" of volume. Thus, the density (d) is the mass (m) divided by the volume (v):
d =m/v
If the mass is 40.0 mg = 0.04 g, and the density is 0.20 g/cm³, the volume is:
0.20 = 0.04/v
v = 0.04/0.20
v = 0.20 cm³
B) The surface area (S) is the are that is presented in each gram of the material, so, it's the area (a) divided by the mass (m):
S = a/m
If the mass is 40.0 mg = 0.04 g, and the surface area is 1242 m²/g, so:
1242 = a/0.04
a = 49.7 m²
C) The percent of mercury removed is the mass removed divided by the initial mass, this multiplied by 100%. The mass removed is the initial mass (m0) less the final mass (m), so:
%removed = [(7.748 - 0.001)/7.748] *00%
%removed = 99.99%
D) The final mass of the spongy material is it mass (10 mg) plus the mass removed of the mercury (7.748 - 0.001 = 7.747 mg), so:
m = 10 + 7.747
m = 17.747 mg
m = 17.7 mg
Get a magnet in a bag (inside out) and move the magnet all over the sand/iron and you can collect all the iron and turn the bag right side out and zip up the bag. Now you have the sand and iron separated and it will be harder to accidentally mix them later.