1. Substances can be classified as and 2. is a liquid non-metal. 3. The elements are arranged in a table called the 4. Calcium has a valency of
Answers
Answer:
1 Pure substances can be either chemical compounds or elements. Compounds can be broken down into elements by chemical reactions, but elements cannot be separated into simpler substances by chemical means. The properties of substances can be classified as either physical or chemical.
2 One non-metal, bromine, is a liquid at room temperature. The other non-metals are solids at room temperature, including carbon and sulfur.
3 The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
4 2
Atomic Structure | Exercise
Elements/Radicals Symbol Valency
1. Potassium K 1
2. Sodium Na 1
3. Hydrogen H 1
4. Calcium Ca 2
Explanation:
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