The commonly used coolant in refrigerators is
1). Ammonia
2). Nitrogen
3). Freon
4). Oxygen
1. The mass number of a nucleus is.
2. The filter over which sewage is sprinkled is called as
3. A change in which one or more new substances are formed is called _________.
4. The iron ore magnetite consists of
5. The manufacture of iron from iron ore involves the process of
7. Which of the following is not present in German silver
8. Iodex, a pain relief balm, hasthe smellof