By what two characteristics are all the elements of the periodic table placed in

How is an emission spectrum of an element generated?

Ok so this is kind of a weird question so ... yeah. Anyway, I'm homeschooled but all my friends are getting ready for homecoming and I'm like I want to go to homecoming but I can't because ... I'm homeschooled.

Which statement best describes a solution containing a strong base? A. the solution is dilute B. The solution is concentrated C. a small amount of the base dissociates in solution D nearly all of the base dissociates in solution

Describe the motion of the gas particles.

In an experiment, 3.25 g of NH3 are allowed to react with 3.50 g of O2. 4NH3 + 5O2 > 4NO + 6H2O a. Which reactant is the limiting reagent? O2 b. How many grams of NO are formed

In which compound does the bond between the atoms have the least ionic character? 1. hf 2. hcl 3. hbr 4. hi?

When a hypothesis is tested and shown to be incorrect is the experiment a failure?

A homogeneous mixture consists of 12% ethanol, 28% methanol and 60% water. which of these is the solvent for the mixture? A. ethanol and methanol B. methanol C. ethanol D. water

A gas that has a volume of 28.0 liters, a temperature of 45.0 °C, and an unknown pressure has its volume increased to 34.0 liters and its temperature decreased to 35.0 °C. If I measure the pressure after the change to be 2.

How many atoms are in 4 HNO³?