Iwould like to know the definitions of theses words

metal- a solid material that is typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity

non-metals- an element or substance that is not a metal.

metaloids-  an element properties are intermediate between those of metals and solid nonmetals or semiconductors.

substance- a particular kind of matter with uniform properties.

physical properties- any property that is measurable, whose value describes a state of a physical system

luster- a gentle sheen or soft glow, especially that of a partly reflective surface.

conductivity- the degree to which a specified material conducts electricity, calculated as the ratio of the current density in the material to the electric field that causes the flow of current. It is the reciprocal of the resistivity.

i think is conclusions.i think so

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