Scientific Problem Solving and The Basics
What is a hypothesis?
an educated guess
What are the four different states of matter?
solid, liquid, gas, and plasma
What are the vertical columns called on the periodic table? What do they tell us?
Group
They have similar chemical properties and react with other elements in similar ways
Do endothermic reactions absorb or release energy?
Absorb
What is matter?
Anything that has mass and takes up space
What is it called when matter changes from solid to liquid?
Melting
In an element, the atomic number is equal to the number of _______ in the atom.
Protons
What are 3 signs a chemical reaction has occurred?
Color, state of matter, odor
What is the difference between an independent and a dependent variable?
In an experiment, you manipulate the independent variable and measure the outcome in the dependent variable
What is it called when matter changes from gas to liquid?
Condensation
What side of the periodic table are metals and what are some of their chemical properties?
Left side
Metals are shiny and conduct thermal energy or electricity
Balance the following reaction:
__ N2 + __Cl2 --> __ NCl3
_1_ N2 + _3_Cl2 --> _2_ NCl3
What is the difference between a physical property and a chemical property?
A physical property is a characteristic of matter that you can observe or measure without changing the identity of the matter.
A chemical property is a characteristic of matter that you can observe or measure as it changes to a different type of matter
Describe the particle motion, volume, and shape of particles in the liquid state of matter.
Particles move freely past other particles
It has no definite shape but does have a definite volume
What part of the atom is involved with bonding?
Electrons
A _______ reaction is where two or more substances combine and form one compound
Synthesis
What are the 6 steps of the scientific method in order?
1. ask a question
2. hypothesize and predict
3. test hypothesis
4. analyze results
5. draw conclusions
6. communicate results
What is the phase change called when matter changes from a solid to a gas? What is an example?
sublimation (ex. dry ice)
In which type of chemical bond to elements share one or more pairs of electrons?
Covalent Bond
A _____ _______ reaction is a reaction where the negative ions in two compounds switch places, forming two new compounds
Double Replacement