Which of the following involve chemical changes?

1. a carrot being digested

2. a piece of wood burning

3. a piece of chocolate melting

Frequency of Deer at Local Pond Date Daily High Number of Deer Temperature (°F) Seen at Pond 45 7 January 1 February 1 March 1 52 10 61 14 73 22 April 1 May 1 83 32 A scientist observed the number of deer that came to drink at a local pond on five

What mass of hydrogen chloride is formed when 1 mole of hydrogen reacts with 1 mole of chlorine?

A large deposit of bauxite a mineral containing aluminium was found in your community. The deposit crosses a nature preserve. A company would like to mine the bauxite in order to extract the aluminium for use in synthetic materials.

The density of ethanol is 0.789g/ml at 20°c. find the mass of a sample of ethanol that has a volume of 150.0 ml at this temperature.

Calculate the molarity of a solution of sodium hydroxide if it contains 0.5 moles in 75ml of solution.

How many moles of CO will be produced, if 32.5grams of H2O are produced? C6H6S+6O2=>6CO+3H2O+SO3

Identify and briefly describe two ecosystems in your community that are beyond schoolyard

Is N2H2 a ionic compound?

What do Lewis dot structures show?

300 grams of a compound which contains only carbon, hydrogen and oxygen is analyzed and found to contain the exact same percentage of carbon as it has oxygen. The percentage of hydrogen is known to be 5.98823%.