Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_21 (covalent__single_bond_ VARCHAR, name VARCHAR)
### Question:
What is the covalent (single bond) value of sodium?
### Answer:
SELECT covalent__single_bond_ FROM table_name_21 WHERE name = "sodium"