Which of the following has a higher electronegativity oxygen or selenium?

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland

What is a metal replacement reaction