Elements tend to decrease in metallic properties

pls answer fast pls pls pls

yes

Explanation:

the metallic properties of elements tends to decrease across a period and increase down a group.

yes

Explanation:

elements having low elctronegativity tend to have more metallic properties

1.43 x 10^-11 j the guy commented the awnser just making sure u see it .

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