81. What element has the electron configuration 1s²2s²2pº3s 3p?

a. nitrogen

c. silicon

b. selenium

d. silver

Fe2O3 + H2SO4à Fe2 (SO4) 3 + H2O For this unbalanced chemical equation, what is the coefficient for water when the equation is balanced?

Which if these is an iconic compound? CO NO2 LiCI SO3

Explain why the periodic table is not a normal table of rows and columns

Which of these is NOT a falsifiable hypothesis? A) Species change over time. B) Inherited characteristics are carried on factors called genes. C) Cells come from other cells. D) Life on earth was seeded by extraterrestrial aliens.

Why do the atoms in a piece of copper metal have no net charge?

At equilibrium, a. the forward reaction rate is lower than the reverse reaction rate. b. the forward reaction rate is higher than the reverse reaction rate. c. the forward reaction rate is equal to the reverse reaction rate. d.

Given the balanced equation representing a reaction: 4Al (s) + 3O2 (g) - - >2Al2O3 (s) Which type of chemical reaction is represented by this equation? (1) double replacement (2) single replacement (3) substitution (4) synthesis

A helium balloon has a volume of 735 mL when it is at ground level. The balloon is transported to an elevation of 5km, where the pressure is only 0.8atm. At this altitude the gas occupies a volume of 1286mL.

If a mixture contains 75% of one compound and 25% of its enantiomer what is the e. e

White light, which consists of all frequencies, forms which type of spectrum?