What defines an exothermic reaction?

O A. A reaction that needs heat added

O B. A reaction that possesses enthalpy

O c. A reaction that relies on collisions

O D. A reaction that produces heat

A substance made of metal atoms only?

Which scientist observed that compounds are always joined together in fixed ratios? A. Boyle B. Bohr C. Lavoisier D. Proust

What are the four major models of an atom that led up to the modern electron cloud model of the atom?

What is the definition of radiation

When you push down on a block resting on a table, block atoms and table atoms that are in contact with one another A. move closer to one another B. break their bonds with one another C. move past each other D. maintain their positions

How many moles are in 4,55 X 10^23 molecules of CO2 (rounded)

In standardization of NaOH solution, a student found that 25.55cm3 of base neutralized exactly 21.35cm3 of 0.12M HCl. Find the molarity of the NaOH.

Which is a base unit in SI? A. centimeter B. kilogram C. gram D. grams/milliliter

The primary mechanism for converting atmospheric carbon into usable forms for life on earth is achieved by

For a particular collision, she detects the emitted products and find 15 protons, 2 antiprotons, 7 positrons, and 24 neutral particles. How many electrons are also emitted