Investigations were carried out in a science lab to explore the topic of chemical and physical changes. investigation a step 1. add 5 tsp. salt to 100 ml warm water and stir until most or all of the salt is no longer visible. step 2. heat the salt solution on a burner until only a white solid remains. investigation b step 1. mix 10 tsp. white sugar into 100 ml water and stir until most or all of the sugar is no longer visible. step 2. heat the sugar solution on a burner until the solution thickens and turns brown. in which step(s) did a chemical change most likely occur?

Answer : B) In step 2, there was a chemical change which was observed in sugar.

Explanation : In A step 2 there was a physical change that was seen. By just boiling the dissolved salt solution salt was obtained. Therefore, it is a physical change. In B step 2 there was a chemical change seen as sugar solution was thickened and turned brown. It was not obtained in its original form; there was a chemical reaction that took place during sugar evaporation. As chemical change is the one where the reaction is irreversible.

Therefore only in B step 2 there was a chemical change that was observed.

Answer is: B step 2,  Heat the sugar solution on a burner until the solution thickens and turns brown.

This is chemical change (chemical reaction), because new substance (caramel) is formed, the atoms are rearranged and the reaction is followed by an energy change.

In other examples physical change is occured.

The same substance is present before and after the psysical change, just with different form or state of matter. Making mixture is physical change (physical change is reversible).

answer: at room temperature (roughly 20 degrees c), you can dissolve 203.9 grams (or 200 grams) of sugar in 100 ml of water. as water temperature increases, the amount of sugar that will dissolve increases, up to about 500 grams of sugar in 100 ml water at 100 degrees c.

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: