STATEMENT 1: Elements cannot be broken down into simpler substances.
STATEMENT 2: Mixtures are homogenous and heterogenous in nature.
STATEMENT 3: Constituents of a compound can be separated by chemical means.
STATEMENT 4: A mixture has a variable composition.
statement 1,2, and 3 are true.
Elements are the basic fundamental units which build all matter, they cannot be broken down into simpler substances. Mixtures with a uniform composition of constituents are termed as homogeneous and the ones with a non-uniform composition are termed as heterogeneous. Hence, some mixtures have a variable composition while other have a consistent composition throughout. Constituents of a compound are chemically bonded together and hence cannot be separated by physical means. They can only be separated by chemical means.