Question | Answer |
which axis of a graph is the dependent variable plotted? | vertical |
On which axis of a graph is the independent variable plotted? | horizontal |
step that results in a hypothesis being “educated?” | gathering information |
hypothesis | an educated guess for a question or problem |
scientific process often begins with | posing questions |
A basketball has a mass of 260 grams | quantitative observation |
kilo | 1,000 |
measure of the amount of matter in an object | mass |
used to measure the mass of an object | triple beam balance |
used to measure the volume of a liquid | graduated cylinder |
particles in atoms have a negative electric charge | electrons |
number of protons equals the number of | electrons |
only particles found in the nucleus of an atom | protons and neutrons |
have no charge; they are considered neutral | neutrons |
located outside of the nucleus, orbiting around it | electrons |
positively charged particles in the nucleus of an atom | protons |
Neutrons are located | in the nucleus |
atomic number | number of protons |
most reactive metals | group 1 |
Elements are in a particular column of the periodic table because | number of valence electrons |
noble gases are located in group | group 18 |
Which type of element do groups 13-17 all contain? | metalloids |
How many valence electrons does an atom of Chlorine have? | 7 |
How many protons does an atom of Boron have? | 5 |
How many total electrons does an atom of Helium have? | 2 |
Atoms of the element Carbon have how many valence electrons? | 4 |
Group 17, the halogens, contains mostly which type of element? | nonmetals |
What happens when chemical bonds break and new bonds form? | chemical reaction |
what does the law of conservation of mass mean? | Matter is not created or destroyed |
Ionic bonds form between | metal and nonmetal |
A chemical bond formed when two atoms share electrons | covalent |
When an atom gains an electron, it becomes a | negative ion |
ionic compound | NaCl |
attractive force between atoms that have transferred valence electrons | ionic bond |
When an atom loses one or more electrons | positive ion |
Covalent compounds form between | nonmetals |
covalent compound | C3H8O |
mixture that appears uniform throughout | solution |
solute is present | in a smaller amount |
molecules move from an area of __ concentration to an area of ___ concentration | higher, lower |
osmosis is the process of _____ movement | water |
hypotonic solution | water moves into the cell |
hypertonic solution | water moves out of the cell |
isotonic solution | water moves equally in and out of cell |
solute | gets dissolved |
solvent | does the dissolving |
solvent is present | in a larger amount |
acids produce __ ions | hydrogen |
bases produce __ ions | hydroxide |
pH scale measures | concentration of hydrogen ions |
Concentration of H ions is high | pH is low |
Concentration of H ions is low | pH is high |
material used to increase the rate of a chemical reaction | catalyst |
how to supply activation energy to begin a reaction | heat it up |
minimum amount of energy that has to be added to start a reaction | activation energy |
increase in temperature affects the rate of a chemical reaction | gives particles more energy |
increase in surface area affects the rate of a chemical reaction | speeds up the reaction |
increase in concentration of reactants affects the rate of a chemical reaction | supplies more particles to react |