Ethylene- C2H4 = 85.7% Carbon and 14.3% Hydrogen
Find the atomic masses for each element and multiply it by the number of atoms in the compound, then add.
C- 12.0 * 2= 24.0
H- 1.00 * 4= 4.00
-----------------------
28.0
Take the masses for each element and divide it by the total mass. Then change the answer to get the percent.
C 24.0 / 28.0= .857 = 85.7%
H 4.00 / 28.0= .143 = 14.3%
<h3>
Ethylene is 85.7% Carbon and 14.3% Hydrogen </h3>
Answer: 1) only a salt and water
An acid and base reacts together to undergo neutralization to form salt and water.

where HCl is an acid and NaOH is a base to form salt (NaCl) and water
.
Answer: 2) The formula of the hydrogen ion is often written as
.
All acids dissociate in water to give
ions.
Answer: 3) Arrhenius acids are substances that ionizes to yield protons in aqueous solution.

Arrhenius bases are substance that ionizes to yield hydroxide ions in aqueous solution.

Answer: 4) A conjugate acid base pair transfers hydrogen ion.
Here
accepts a proton and thus act as a base and the corresponding
is its conjugate acid.
Answer: 5) Bronsted Lowry acid is a substance that donates protons. Bronsted Lowry base is a substance that accepts protons.
and 

is a acid which accepts proton and thus acts as base to form conjugate acid
.
Answer:
Caesium and Barium
Explanation:
Once again, if you look at the periodic table, you can see that Caesium and Barium are in the same period (Period 6).
<em>Feel free to mark this as brainliest! :D</em>
first find the atomic weight of CH3 which would be
atomic weight: 12.011 (3×1.008) = 36.32 g/mol
then find the moles in the given mass
36.32 ÷ 45.7 = 0.794
I HOPE I'M NOT WRONG I HAVENT DONE CHEM IN SO LONG