Periodicity is best defined as: the fact that elements increase in atomic mass in a regular way
the repeating nature of physical and chemical properties with increasing atomic number
the regular growth of atomic size with atomic mass
the consistent decrease of nuclear charge with atomic mass
the repeating nature of atomic nuclear structure

a graduated cylinder.

explanation:

when—without warning—something provokes your anger, you may struggle not to succumb to it. since what typically makes you mad is feeling powerless in the face of what seems unfair, your anger is mostly an attempt at a “quick fix” to right the balance. it’s as though you’re raising a fist in protest, proclaiming that you’re not going to capitulate to such injustice.

there are, however, a multitude of problems related to this immediate, push-back reaction of anger. and probably the key one is that almost never does it resolve the issue that gave rise to it. such reactive anger is probably best understood as self-defeating. as david burns, the author of the seminal self- book feeling good, observes: if realistically, acting on your anger is to make any sense, it needs to meet two criteria—which, in almost every case, is frankly impossible. that is, your anger must:

be directed toward a person who has intentionally (and needlessly) behaved in a hurtful way toward you; and

be beneficial or advantageous to you (i.e., assist you in achieving a desired goal).

i think you’ll agree that only rarely can you claim that your anger is both warranted and , whether to yourself or the relationship.

so let me offer you a two-step alternative to abandoning your better judgment and giving in to the temptation of anger—one that should neutralize your anger in seconds. or, when you’re really angry, in minutes.

but keep in mind that you must really want to execute these steps, be sufficiently motivated to perform them. which means overcoming more unconscious resistance than you might ever have imagined. because there are many immediate “advantages” of anger that can interfere with your resolve, i’ll suggest a few of them that might interfere with your employing this powerful method to rid yourself of counter-productive anger.

explanation:

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