A refracting telescope uses convex lenses to gather a large amount of light and focus it onto a small area while a reflecting telescope the mirror instead of an objective lens they are also similar because like the lenses in a refracting telescope the mirror in a reflecting telescope focuses a large amount of light onto a small area.
Answer:4
Explanation:
If we carefully observe the electronegativity of the elements in question
P-2.19
N-3.04
C-2.55
Si-1.9
H-2.2
SiH4 is definitely more polar than CH4 hence greater dipole forces of a higher boiling point. NH3 is more polar than PH3 hence NH3 has greater dipole forces and a higher boiling point. Electronegative differences influences the polarity of a bond. The greater the electro negativity difference between bonding atoms, the greater the dipole forces and the greater the boiling point.
Answer:
Half-life = 3 minutes
Explanation:
Using the radioactive decay equation we can solve for reaction constant, k. And by using:
K = ln2 / Half-life
We can find half-life of polonium-218
Radioactive decay:
Ln[A] = -kt + ln [A]₀
Where:
[A] could be taken as mass of polonium after t time: 1.0mg
k is Reaction constant, our incognite
t are 12 min
[A]₀ initial amount of polonium-218: 16mg
Ln[A] = -kt + ln [A]₀
Ln[1.0mg] = -k*12min + ln [16mg]
-2.7726 = - k*12min
k = 0.231min⁻¹
Half-life = ln 2 / 0.231min⁻¹
<h3>Half-life = 3 minutes</h3>
Filtration can be used to separate an insoluble solid from a liquid, or a precipitate from the reaction mixture in which it formed. The solid which collects in the filter paper<span> is called the residue. The clear liquid which passes through the </span>filter paper<span> is called the filtrate.</span>
MH₂ = 2×mH = 2×1g = 2 g/mol
