Chemistry Q1 Final Flashcards
Chemistry
The study of the properties, ability to transform, and the energy involved in the transformation of matter.
Matter
Anything that has mass and takes up space
Mass
A measure of the amount of mass in an object
Energy
The ability to do work or cause change in matter.
Weight
A measure of the gravitational force on an object. Measured in Newtons (N).
States of Matter
Solid, liquid, gas, (plasma)
What does changing states of matter require?
Energy transfer. Either into the system or out of the system.
What Are Physical Properties? Examples
Properties that can be observed without changing the identity of the substance. Color, length, weight, volume, density, boiling point, odor, melting point, texture.
Length
Greatest measurement of the object
Volume. How is it measured?
The amount of space the matter takes up. Measured geometrically or with water displacement.
Density
ratio of mass to volume. Density = weight/volume.
What Are Chemical Properties? Examples.
Properties that describe a substance’s ability to change to a new substance with different properties. Flammability, reactivity.
Elements
A substance that can’t be broken down into smaller substances by physical or chemical means. They are the building blocks of other substances. They are made entirely from one type of atom.
Atoms
Smallest unit of an element that has the identity of the element
Protons
Positively charged in the nucleus of the atom.
Neutrons
Neutral charge particles in the nucleus of the atom.
Electrons
Negatively charged particles found outside the nucleus of atoms.
Atomic Number. Where is it located?
Number of protons in the atom’s nucleus. Top of the element square.
Symbol
Used as a short-hand and in chemical equations.
Mass number. Where is it located?
The number of protons and neutrons in the nucleus. Bottom of the element square.
How is the Periodic Table Organized?
By atomic number (number of protons) - left to right, top to bottom. Elements in each column are called a group/family. They have similar chemical and physical properties. Periods (horizontal rows) show the number of energy levels (shells). Ex. row 1 has 1 energy level.
Reactivity
How likely an element is to form a compound with another element.
How do we determine reactivity on bohr models?
Look at the valence electrons (the electrons on the last energy level)
Nitrogen has an atomic number of 7 and an atomic mass of 14. Unless told otherwise, how many electrons can we assume it has? Neutrons?
7 electrons. 7 neutrons.
Pure substance
A sample of matter that has specific chemical and physical properties. They are made up of only one type of matter throughout. They can be groups of individual atoms that aren’t joined together or atoms that are joined together. Elements.
Molecule
Two or more atoms that are held together by chemical bonds. Smallest part of a compound that keeps the properties of the compound.
Chemical Bond
The attractive force that holds atoms together. Not a physical thing.
Compound
A pure substance made up of two or more different types of atoms joined by a chemical bond. Always form in a fixed ratio.
Crystal
A substance in which the particles are arranged in an orderly, geometric, and repeating pattern.
Extended Structure
A substance arranged in a repeating, orderly fashion.
Heterogenous Mixture
unevenly distributed mixture
Homogenous Mixture
evenly distributed mixture
All compounds are molecules, but not all molecules are compounds. True or False?
True
What things cause the differences in properties of pure substances?
- The types of atoms they contain and how they’re connected. 2. The chemical bonds are stronger in different substances. 3. There is a difference in the structure of the two substances.
Chemical Reaction
The process in which the building blocks of matter- atoms- are rearranged to produce different substances.
Reactants
The original substance/substances in a chemical reaction
Products
The substance/substances formed in a chemical reaction
When substances are mixed together, does a chemical change always occur?
No
What happens to the atoms in a chemical reaction?
They regroup into different particles to form new substances. The new particles could be atoms, molecules, or subunits of extended structures.
Chemical formula
A combination of chemical symbols and numbers that represent a single unit of a substance. It shows the exact atoms in each molecule or unit. The atoms are always present in the same ratio.
Subscript
Number below and to the right of the symbol. Tells how many of the element there are.
Parentheses
Represents atoms that are held together as a group within the compound.
How many of each type of atom are there? Al,2(SO,4),3
2 Al, 3 S, 12 O
Balance the Equation. __C + __S,8 = __CS,2
- 4.
System
A set of interacting parts. They can include matter, energy, and information. It has inputs (things entered into the system) and outputs (things that exit the system).
Convection
Thermal energy is transferred through matter that flows. Cold particles sink, causing warm particles to rise.
Conduction
Thermal energy is transferred as particles bump into one another. Warmer particles move more rapidly, bumping into cooler particles and transferring energy.
Radiation
Energy is transferred by light or other electromagnetic radiation. The radiation travels until it’s absorbed by a particle and turned into thermal energy.
Chemical Processes
Transform the energy stored in chemical bonds or in the arrangement of molecules into thermal energy. They include chemical reactions and physical changes.
Do particles move faster in warm or cool objects? Do they flow from the cooler object to the warmer one….or the warmer one to the cooler one?
Warm. Warmer object to cooler object.
If it releases thermal energy, it’s a temp _____. If it absorbs thermal energy, it’s a temp ______.
Increase. Decrease.
