Why is lead harmful to humans.

How many covalent bonds does and oxygen stone usually make in forming covalent compounds? a) 5 b) 3 c) 2 d) 4 e) 1

What noble gas has the same ground state electron configuration as the oxygen in thionyl chloride?

The diagram shows an electron shell model of a sodium atom. A central purple circle labeled N a has 3 concentric rings around it. The inner ring has 2 small green spheres. The middle ring has 8 small green spheres.

The emission spectrum of hydrogen shows discrete, bright, colored lines. Which characteristic of the Bohr model is best supported by this observation?

Compared to winds on the earth the winds on Saturn are much stronger. True or False?

How do you know if the reaction is exothermic or endothermic if both phase are same?

How many elements are in a set whole numbers between 3 and 15

Calculate the percent activity of the radioactive isotope strontium-89 remaining after 5 half-lives.

Describe 2 theories for yawning

When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. the reason for this is?