Module #3: Atoms and Molecules Flashcards
Element
Any substance that cannot be decomposed into less massive substances
Compounds
Substances that can be decomposed into elements by chemical means
The Law of Definite Proportions
The proportion of elements in any compound is always the same
What are Metals?
Usually malleable, have luster, and are able to conduct electricity
What are Nonmetals?
Typically brittle, lack luster, and do not conduct electricity
What are Metalloids?
Elements that have some metal properties and some nonmetal properties
The Law of Multiple Proportions
If two elements combine to form different compounds, the ratio of masses of the second element that react with the fixed mass of the first element will be a simple, whole-number ratio
Isotopes
Certain atoms within an element which are heavier than other atoms in the same element
Ionic Compound
A compound that contains at least one metal atom and at least one nonmetal allowing it to conduct electricity
Covalent Compound
A compound which is made up solely of nonmetal atoms disabling it of the ability to conduct electricity
The Naming Principles of Ionic Compounds
- Start with the name of the first atom in the molecule
- Take the next atom in the molecule and replace its ending with an “ide” suffix
- Putting these two words together gives you the compound’s name
What are Nonmetals?
They’re typically brittle, they lack luster, and do not conduct electricity
What are Metalloids?
Elements that have some metal properties and some nonmetal properties
The Continuous Theory of Matter
The theory that substances were composed of long, unbroken blobs of matter.
The Law of Mass Conservation
Matter cannot be created or destroyed; it can only change forms
What were Dalton’s Assumptions?
- All elements are composed of small, indivisible particles called “atoms”
- All atoms of the same element have exactly the same properties
- Atoms of different elements have different properties
- Compounds are formed when atoms are joined together. Since atoms are indivisible, they can only join together in simple, whole-number ratios
What are the naming conventions of covalent molecules?
They’re the same as the ionic conventions except for the fact that you add the number prefixes (mono, di, tri, etc.) in front of the element names