What property of normal rainfall makes it
especially useful in the
chemical weathering of
certain rocks?

Minerals in rocks may react with the rainwater, causing the rock to be weathered. Some types of rock are easily weathered by chemicals. For example, limestone and chalk are mostly calcium carbonate. When acidic rainwater falls on limestone or chalk, a chemical reaction happens.

in about winter like late november to january

sir frederic attributed inaccuracies to schemas. memory reconstruction is one part actual events and one part personal schema, which can result in inaccuracies when memories are reconstructed.