SCIENCE: Arch, loop and whorl are all parts of what?

Questions

If a dish is served A la Chantilly, what would be its main ingredient?

The Riksdag is the parliament of which country?

In which country would you find the site of the World War One Battle of Tannenberg?

In which musical work of 1925 would you hear the song Summertime?

Who painted Les Parapluies in about 1883?