For a solar eclipse to occur,

a. the sun must be directly between earth and the moon.

b. the moon must be directly between earth and the sun.

c. the moon must be directly behind earth.

d. earth must be directly between the sun and the moon.

State one medical use of radioactive isotopes

An electrically neutral atom has the following electron configuration 1s22s22p63s2. what is the name of this atom? a. oxygen b. magnesium c. sodium d. aluminum

Determine an empirical formula from each set of percent composition data. 1. 18.27% K, 59.30% I, 22.43% 0

What are the three components of the fire triangle?

g A chemistry student needs of thiophene for an experiment. She has available of a w/w solution of thiophene in benzene. Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button.

Radium-223 is a radioactive isotope with a half-life of 11.4 days. how long (in days) will it be before 87.5% of the sample has decayed?

Which kind of reaction is shown below? 2H2O2 → 2H2O + O2

Phosphorus has the molecular formula p4, and sulfur has the molecular formula s8. how many grams of phosphorus contain the same number of molecules as 7.88 g of sulfur?

Latitude is the only factor that determines the temperature of a region true or false?

What is the overall reaction for lactic acid fermentation?