Which are exmaples of chemical change? •baking cookies

• The statue of liberty's metal tarnishes from copper to green

• cold butter melts into liquid when heated

•salt is dissolved into freshwater

•Food scraps decompose into fertilizer in a compost pile

• frying changes the color and texture of an egg

•ocean water evaporates to water vapor on a hot day

•lighting a match

Which type of orbits are found in the principal energy level n = 2 a - s b - s, f c - s, d d - s, p e - s, p, d

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it