When sodium is excited in a flame, two ultraviolet spectral lines at lambda - 372.1 nm and lambda = 376.4 nm respectively are emitted. which wavelength represented photons?

a) higher energy?

b) longer wavelengths?

c) higher frequences?

The composition of a compound is 20.01% carbon and 79.99% oxygen by mass. what is its empirical formula?

What is the formula for tin (ll) chromate

How many electrons are needed in the outer energy levels of most atoms to be chemically stable?

A scientist in London and a scientist in California both conducted independent investigations that produced similar results.

What determines the state of a substance

1. Which of the following species determines the chemical properties of an atom? A. Electron B. Neutron C. Nucleus D. Proton 2. The following glasswares are used to measure the volume of liquids except A. graduated beaker B. pipette C. test tube D.

A sample of a certain material has a mass of 2.03 x 10-3 g. calculate the volume of the sample, given the density is 9.133 x 10-1 g/cm3.

What happens to a reactant molecules when forming product molecules

Which is the atomic number of an atom with six valence electrons

O2 + CS2 → CO2 + SO2 Which of the following shows the equation balanced?