How many neutrons are there in an atom of lead whose mass number is 208?

Which are true statements? Check all that apply. A. Moles are counted in kilograms. B. A mole always weighs 6.02 * 1023 g. C. The mass of 1 mol is the same as the atomic mass in grams. D. Avogadro's number is 6.02 * 1023.

Which choice is an abiotic factor of an ecosystem A. dogs B. fungi C. ants D. minerals

Which two substances are covalent compounds? (1) C6H12O6 (s) and KI (s) (2) C6H12O (s) and HCl (g) (3) KI (s) and NaCl (s) (4) NaCl (s) and HCl (g)

Rasheed calculates that his chemical reaction should produce 4 moles of product, but when he does the experiment, he gets only 3 moles. What is his percent yield?

As a star increases in brightness, which value becomes smaller? A. density B. magnitude C. temperature D. luminosity

A chemistry teacher needs to determine what quantity of sodium hydroxide to order

Never trust Wikipedia .

Which is the molar mass of BF3?

Mg3 (Si2O5) 2 (OH) 2 There are. 0893 moles of magnesium how many moles of silicon are there in the sample?

The volume of a gas is reduced from 4 L to 0.5 L while the temperature is held constant. How does the gas pressure change? It increases by a factor of two. It increases by a factor of eight. It decreases by a factor of eight.