D. the reflection of each concave lens makes the object appear larger
Hi There! :)
<span>Which elements in the periodic table are metalloids or have semimetallic properties?
</span><span>Boron, Silicon, Germanium, Arsenic, Antimony, and Polonium are all metalloids. Some people consider Astatine a metalloid</span>
Nuclear fission is the splitting of atoms
Missing question: <span>A 5.00 L sample of O2 at a given temperature and pressure contains a 1.08x10^23 molecules. How many molecules would be contained in each of the following at the same temperature and pressure? </span>
a) 5.00 L H2.
<span>b) 5.00 L CO2.
Use </span>Avogadro's Law: The Volume Amount Law: <span>equal </span>volumes<span> of all gases, at the same temperature and pressure, have the same </span>number<span> of molecules. Because hydrogen and carbon(IV) oxide are gases, number of molecules are the same as number of oxygen molecules, so:
a) N(H</span>₂) = 1.08·10²³.
b) N(CO₂) = 1.08·10²³
<span>85% ethanol | 25% ethanol | 50% ethanol
x | y | 20 gal
use x and y because you don;t know how much she needs.
0.85x | 0.25y | 20(0.5)
85% is 85/100 or 0.85, and you need that much of x, same goes for the 25% and 50% mixtures so now you can make up 2 equations
1) x + y = 20 2) 0.85x + 0.25y= 10 (you get 10 when you multiply 20 by 0.5) now you can solve for x or y using substitution.
first rewrite 1) in terms of x or y: x+ y= 20 ----> y= 20 - x now you can substitute 20- x for y in the second equation.. 0.85x + 0.25y= 10 0.85x + 0.25(20-x)= 10 distribute here..(0.25 * 20 and 0.25 * (-x) ) 0.85x + 5 - 0.25x = 10 combine like terms 0.6x +5 = 10 move the 5 over to the other side 0.6x= 10 -5 0.6x = 5 divide both sides by 0.6 x= 25/3 or 8.3 now you know the amount of x so you can substitue this back into the first equation to find y. 0.85x + 0.25y= 10 0.85(25/3) +0.25y= 10 85/12 + 0.25y= 10 0.25y = 10- 85/12 0.25y= 35/12 y= 35/3 or 11.6 you can check by putting these values into the euations: 1) x+ y= 20 25/3 + 35/3 =20 20= 20 good so far 2) 0.85x + 0.25y= 10 0.85(25/3) + 0.25(35/3)=10 10 = 10
so our values for x and y work
x= 25/3 and y= 35/3</span>
