CREATE TABLE "atomic_radii" (
  "number" real,
  "symbol" text,
  "name" text,
  "empirical" text,
  "calculated" text,
  "van_der_waals" text,
  "covalent_single_bond" text,
  "covalent_triple_bond" text
);

Question: What is the symbol of the element with an empirical t of 190 and a calculated value of 135?
SQL: SELECT "symbol" FROM "atomic_radii" WHERE "empirical"='190' AND "calculated"='135';

Question: What is the name of the element with a calculated value of 56?
SQL: SELECT "name" FROM "atomic_radii" WHERE "calculated"='56';

Question: What is the covalent (single bond) value of sodium?
SQL: SELECT "covalent_single_bond" FROM "atomic_radii" WHERE "name"='sodium';