Answer these questions based on the Periodic Table entry for sodium: 11
Na
22.991
What is the atomic mass?
What is the atomic number?
How many neutrons does sodium have?
What is the chemical symbol for sodium?
How many protons does sodium have?
How many electrons does it have in the n=2 orbit?

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2