Two or more elements make up a compound
Answer:
Double replacement.
Explanation:
Chemical Reactions => Double Replacement Reactions.
Let's call Ted as T, Emily as E, Jack as J, and Brenda as B.
In the first match, we have T and E playing against J and B; and in the second match, we have T and B playing against J and E. We can state a 'reaction' of this if the first match would be the reactants and the second match the products:

You can note that this is similar to a double replacement reaction, remember that a double-replacement reaction is a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds. The general form of a double-replacement reaction is:

which is similar to the reaction of the game, so the answer would be Double replacement.
Answer:
the standard enthalpy of formation of this isomer of C₈H₁₈ (g) = -375 kj/mol
Explanation:
The given combustion reaction
C₈H₁₈ + 25/2 O₂ → 8 CO₂ + 9 H₂O ............................(1)
Heat of reaction or enthalpy of combustion = -5099.5 kj/mol
from equation (1)
ΔH⁰reaction = (Enthalpy of formation of products - Enthalpy of formation of reactants)
Or, - 5099.5 = [8 x ΔH⁰f(CO₂) +9 x ΔH⁰f(H₂O)] - [ΔH⁰f(C₈H₁₈) + ΔH⁰f(O₂)].................................(2)
Given ΔH⁰f(CO₂) = - 393.5 kj/mol & ΔH⁰f(H₂O) = - 285.8 kj/mol and ΔH⁰f(O₂)= 0
Using equation (2)
ΔH⁰f(C₈H₁₈) = -621 kj/mol
I think so. Half of 90 is 45 so 45 divided by 3 (3 seconds) if 15. 15 meters per second.
<span>It is said
that the carbon atom is a tetra valence which means, it contains 4
covalent bonds that can be bonded with other atoms. Therefore, it needs 4
hydrogen atoms to bind into 1 carbon atom. Carbon Atom contains a total of
6 electrons that occupies the 2 shells which is the K (have 2 electrons)
and L (have 4 electrons) shells. The
outermost shell of carbon atoms that contains 4 electrons is called as
valence shell. In order to complete its octet, carbon Atom needs other
atoms to share their valence electrons.</span>