The decay of which radioisotope can be used to estimate the age of the fossilized remains of an insect?

(1) Rn-222 (3) Co-60

(2) I-131 (4) C-14

500. mL of gas is contained at STP. The volume changes to 560 mL at 20.°C What is the pressure (in atm) ?

What is the Arrhenius definition of a base? A substance that increases H3O + concentration when it is dissolved in water. A substance that increases OH - concentration when it is dissolved in water. A compound that donates protons.

Calculate the ph of a solution that is made by mixing 50.0 ml of 0.14 m acetic acid and 50.0 ml of 0.21 m sodium acetate. express your answer to two decimal places.

The part of the ocean floor that separates the oceanic rise from the thick continental crust and is between the shoreline and the continental shelf break is called the continental A) rise. B) shelf. C) slope. D) margin.

Consider this equilibrium: N2 (g) + O 2 (g) 2NO (g). Nitrogen gas and oxygen gas react when placed in a closed container.

Why does the chair in which you are currently sitting retain its same shape over time? Question options: The particles of the chair are strongly held together. The chair is lower in energy than the surrounding environment.

Which of the following is not a benefit provided by a social group A. instinct to run from predators B. access to mates C. protecting young D. learning to recognize predators

Why must an air traffic controller know a plane's velocity

Compare and contrast the two kinds of chemical bonds (ionic and covalent)

If a thin and a thick wire are otherwise identical, what property is lower for the thicker wire? 1. current 2. static charge 3. resistance 4. voltage