Final answer:
To determine which subsets of ℒ^2 are subspaces, we need to check for closure under addition and scalar multiplication, and contain the zero vector. Option C (metal alloys) and Option D (elements) are subspaces of ℒ^2.
Step-by-step explanation:
To determine which of the following subsets of ℒ^2 are subspaces of ℒ^2, we need to identify if they satisfy the three properties of a subspace: closure under addition, closure under scalar multiplication, and contain the zero vector.
- Option A: The set of all compounds containing 2 elements is not closed under addition or scalar multiplication, so it is not a subspace.
- Option B: The set of all heterogeneous mixtures is not closed under addition or scalar multiplication, so it is not a subspace.
- Option C: The set of all metal alloys is closed under addition and scalar multiplication, and contains the zero vector, so it is a subspace.
- Option D: The set of all elements is closed under addition and scalar multiplication, and contains the zero vector, so it is a subspace.
Therefore, Options C and D are subsets of ℒ^2 that are subspaces of ℒ^2.