What do we beileve is at the center of the milky way

A) two stars that have collided together

B) a cluster of stars

C) A black hole

D) A collapsed planet

Calculate the number of moles in each of the following 15.0g NH3

3. A mass of 0.15 ounces is equal to how many grams? A. 0.2352 g B. 0.24 g C. 4.25 g D. 4.3g E. None of the above are correct.

A solution has a ph of 10.20 at 25°c. what is the hydroxide-ion concentration at 25°c?

According to one acid base theory a base is an 1, h2 acceptor 2, h2 donor 3, h + acceptor 4, h + donor

Which of the following atoms releases more energy than oxygen when an electron is added to its valence energy level? Select one: a. helium (He) b. fluorine (F) c. carbon (C) d. nitrogen (N)

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