Which change is exothermic?

a: Icebergs shrink as global temperature rises

b: Solid water turns to liquid water as energy is added

c: Rain becomes sleet when the temperature falls below 0°C

Which class of elements will contain both solids and gases at room temperature? inner transition metals metals metalloids nonmetals

A 2.06g sample of agno3•xh2o is dissolved in an aqueous solution of excess nacl. The resulting agcl precipitate is filtered off and is found to have a mass of 1.32 g. What is the value of x in agno3•xh2o?

Write the electron configuration of the atom in the third row of the periodic table that has the smallest ei4.

Which equation represents a change that results in an increase in disorder? (1) I2 (s) = >I2 (g) (2) CO2 (g) = >CO2 (s) (3) 2Na (s) + Cl2 (g) = >2NaCl (s) (4) 2H2 (g) + O2 (g) = > 2H2O (l)

Jacqueline isolated an interesting new protein from the broth of a yeast culture. After purification of the protein, she requested an amino acid analysis and found that the protein contained 0.48 % tryptophan by weight (tryptophan Mr=204). a.

Which has more atoms, 2moles of carbon or 2 moles of aluminum

At 100 degrees c, water reacts with acetic anhydride to make acetic acid. also, at 100 degrees c, water reacts with acetylsalicylic acid and reverts it to salicylic acid and acetic acid.

What is the valence electron configuration of the group 2a elements?

Which of the following statements about monosaccharide structure is true? A) Aldoses and ketoses differ in the position of their hydroxyl groups. B) Monosaccharides can be classified according to the spatial arrangement of their atoms.

Examples of chemical and physical changes