Unit Test Flashcards
Why do we study chemistry?
- Chem. affects all aspects of life and most natural events.
- Chem. helps explain natural world.
- Studying chem. makes you an informed citizen.
- Connects inanimate world (physics) to the living world (biology)
What is chemistry?
The study of composition (the makeup), structure, and properties of matter and the changes matter undergoes during chemical reactions.
What is matter?
Anything that has mass and takes up space.
What are some examples of matter?
A person, air, blood, a pencil, etc.
What are some examples of things that aren’t matter?
Heat, light, energy, etc.
What are the states of matter?
Solid, liquid, gas, (also plasma)
What measurement system is used in Science?
Metric system
Whats the base unit for mass?
gram (g)
Whats the base unit for volume?
Liter (l)
Whats the base unit for length?
Meter (m)
How do you change a metric system unit?
Multiply or divide by 10.
What is density?
The substance’s mass per unit of volume. The symbol most often used for density is ρ.
How do you calculate Density (g/Ml)?
Density (g/Ml) = mass (g) / volume (Ml)
hint: you can use triangle with mass on top.
What things describe chemisty?
Time, Energy, Temperature, Mole
What is time?
Duration of a process (seconds (s))
What is energy?
Capacity to do work. (Joule (J) or Calories (cal))
What is temperature?
Measure of kinetic energy in particles. (Celcius 0c or Kelvin 273k)
What is mole?
Substance that contains 6.02 * 10^23 particles. (mol)
The quantity amount of substance is a measure of how many atoms or molecules there are. It doesn’t define weight or mass. It’s just a number.
What is the scientific method?
A logical systematic approach to the solution of a scientific problem.
What are the steps of the scientific method?
- Observation of nature (problem)
- Form a hypothesis ( a proposed explanation)
- Experiment and collection of Observations (IV, DV, constants, control)
- Writing conclusion (Summary of results explained)
- Developing theory (Well tested with Repeated trials for broad observations)
- Scientific law (More experiments leading to description of relationships without explanation)
What are the 2 relationships?
Direct and indirect
Whats a direct relationship?
The values increase together
Whats the inverse relationship?
The values negate each other.
What is the independent variable?
Variable changed
Whats the dependent variable?
Variable measured
Whats the controls (constants)?
Things that stay the same in the experiment.
Whats the control group (control)?
The normal IV/ standard not effected by IV
What is the periodic table?
A list of all known elements.
How is the periodic table organized?
Its organized by increasing atomic number.
What are the 3 types of elements on the periodic table?
Metals, Non-metals, and Metalloids.
What is on the left side of the periodic table?
The metals with the greatest metallic properties.
What is on the right side of the periodic table?
The elements with the least metallic properties (Non-metals)
What are the elements in the middle of the periodic table?
Transition elements (properties change from metals to non-metals)
What are metalloids and where are they?
Metalloids are a small group of elements that zigzag between the metals and nonmetals. They have both metallic and nonmetallic propertices.
What are the vertical columns on the periodic table called?
groups or families
What are the horizontal rows on the periodic table called?
periods
If two elements are in the same group or family, what do they have in common?
They have the same number of valence electrons (what determines the elements chemical properties including reactivity)
Where are the valence electrons on the atom?
They are on the outer layer of the atom.