1. Use electron dot structures to predict the formula of the ionic compounds formed when the following elements combine.
a. sodium and bromine
d. aluminum and oxygen
b. sodium and sulfur
e. barium and chlorine
c. calcium and iodine
d. aluminum and oxygen
e. barium and chlorine

the answer is 1 i believe

air

in a tire you fill a tire with air

then a couple days later you check the air pressure in the tire

hope this mark me brainliest

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol