Think about the lab procedure you just read. label each factor below with v for “variable” or c for “constant”. the temperature of the gas: the amount of gas in the tube (in terms of mass and moles): the radius of the tube: the temperature of the gas (changed by the water surrounding it): the type of gas: the pressure of the gas:

the temperature of the gas: V

yhe amount of gas in the tube (in terms of mass and moles): C

the radius of the tube: C

The temperature of the gas (changed by the water surrounding it): V

the type of gas: C

the pressure of the gas: C

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"