<em>From the above options, the best </em><em>Thermal insulator </em><em>will be a </em><em>Plastic cup.</em>
Option (b);
<u>Explanation</u>
Thermal insulators resist to conduct energy or reduction of heat transfer when objects come across in contact with radiation or higher heat object. To conduct energy we need metal or those materials which contain free electrons in it to move from one metal to another.
Plastic doesn't have metallic character so it will resist the heat up to some threshold. Mostly this material is used in separating two current-conducting material. There are many other examples of thermal insulator such as Rubber, fabrics, paper, wood, wool.
The answer is: 27 grams of aluminium.
Balanced chemical reaction: 2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂.
n(H₂) = 1.5 mol; amount of hydrogen.
Form chemical reaction: n(Al) : n(H₂) = 2 : 3.
n(Al) = 2 · 1.5 mol ÷ 3.
n(Al) = 1.0 mol; amount of aluminium.
m(Al) = n(Al) · M(Al).
m(Al) = 1 mol · 27 g/mol.
m(Al) = 27 g; mass of aluminium.
A covalent compound is made when two or more nonmetal atoms bond by sharing valence electrons. The shared valence electrons between two nonmetal atoms is called a covalent bond. Covalent bonds are formed when two atoms begin sharing electrons.
<span>293 grams
The formula for the wavelength of a massive particle is
λ = h/p
where
λ = wavelength
h = Plank constant (6.626070040Ă—10^â’34 J*s)
p = momentum (mass times velocity)
So let's solve for momentum and from there get the mass
λ = h/p
λp = h
p = h/λ
Substitute known values and solve
p = 6.626070040Ă—10^â’34 J*s/3.45Ă—10^-34 m
p = 1.92 J*s/m
Since momentum is the product of mass and velocity, we have
p = M * V
p/V = M
So substitute again, and solve.
p/V = M
1.92 J*s/m / 6.55 m/s = M
1.92 kg*m/s / 6.55 m/s = M
1.92 kg*m/s / 6.55 m/s = M
0.293 kg = M
So the mass is 293 grams</span>
