Word bank: Moderately - Thin - Heat - 88 - Metals - Both - 22 - Malleable - Right -
Luster - Left - Ductile - Opposite - Appearance - (Non-metals) - Periodic-Table
- Electricity - Shiny

Most elements are . The elements on the left side of the stairstep line on the of Elements are metals. Some physical properties of metals
are (shininess), good conductors of and
, and can be hammered into sheets. Non-metals are found
to the of the stair-step line on the Periodic Table of Elements. The characters of nonmetals are
to those of metals. Nonmetals have a dull or
. Nonmetals also break easily and are not
or . Metalloids that are on
sides of the zig-zag line have both properties of metals and nonmetals. Metalloids can be
or dull and can conduct heat and electricity well.

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

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.