A sample of phosphorus-32 has a half-life of 14.28 days. If 55 g of this radioisotope remain unchanged after approximately 57 days, what was the mass of the original sample?

Given the equation: this equation represents the formation of a (1) fluoride ion, which is smaller in radius than a fluorine atom (2) fluoride ion, which is larger in radius than a fluorine atom (3) fluorine atom, which is smaller in radius than a

Which of the following reactions shows that the formation of NO2 requires 33.1 kJ/mol? O A. N (9) + 20 (9) ► NO2 (g) + 33.1 kJ O B. įN2 (g) + O2 (g) + 33.1 kJ → NO2 (9) O c. 1 N2 (9) + O2 (g) NO2 (g) + 33.1 kJ OD. N (g) + O (g) + 33.1 kJ → NO2 (9)

Who said the location and velocity of an electron cant be known

Mushrooms, bread molds, and yeasts are classified together in the fungi kingdom. Specivic characteristics are used to classify these organisms. Which of the following is a characteristic used to classify these organismis as fungi? A.

Which of the following illustrations show atoms of the same element? (Yellow=electrons, red=protons, gray=neutrons).

If a sample containing 2.50 ml of nitroglycerin (density=1.592g/ml) is detonated, how many total moles of gas are produced?

A helium balloon initially at room temperature is dunked into a bucket of liquid nitrogen (T = 77 K). Which of the following will occur?

Which statements indicate what the fossil record suggests about evolution on Earth? Check all that apply. Humans have only recently existed on Earth. Organisms originally lived only in Earth's water. Life on Earth started when water formed on Earth.

What does homogeneous mixture of elements mean

As an acid is added to neutral water the [OH-] will