Both designed a periodic table of elements- Mendeleev designed the first one in order of atomic mass and Moseley designed the modern one in order of atomic number. ... Isotope- Because of the notation and the 13 is not the atomic mass on the periodic table so it is the same element just a different form.
<span>Answer
is: mass of burned butane is 11.6 g.</span>
Chemical reaction: 2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O.
m(butane)
= 50,0 g.
<span>
V(CO</span>₂) = 17,9 L.<span>
n(CO</span>₂) = V(CO₂) ÷
Vm.<span>
n(CO</span>₂) = 17,9 L ÷ 22,4 L/mol.<span>
n(CO</span>₂) = 0,8 mol.<span>
From chemical reaction n(CO</span>₂) :
n(C₄H₁₀) = 8 : 2.<span>
n(C</span>₄H₁₀) =
0,8 mol ÷ 4.<span>
n(C</span>₄H₁₀) =
0,2 mol.<span>
m(C</span>₄H₁₀) =
n(C₄H₁₀) · M(C₄H₁₀).<span>
m(C</span>₄H₁₀) =
0,2 mol · 58 g/mol.<span>
m(C</span>₄H₁₀) =
11,6 g.
Answer: E. It decreases the value of Eact.
Explanation:
Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.
A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and more molecules convert to products.
The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.
Answer:
Chemical change
Explanation:
Matter changes into a new substance by changing into a chemical change. In a chemical change, the substance cannot be changed back to its previous state and a new substance is formed.
Answer:
D. 4/2 He corresponds to an alpha particle.
