click below
click below
Normal Size Small Size show me how
Chemistry Test
Term | Definition |
---|---|
Definition of Chemistry | the study of matter and its behavior under different conditions |
Definition of Matter | makes up everything that takes up space and has weight |
Definition of Elements | a substance that contains only one atom. It can not be broken down in to simpler substances. |
Definition of an Atom | basic building blocks of all matter |
Atomic Number | Number of protons |
Protons | have a positive charge |
Ernest Rutherford | discovered that atoms have a very dense center (a nucleus). He also discovered that the nucleus is positively charged |
Dmitri Mendeleev | he created the periodic table. |
Periodic Table of Elements | organized by weight (left to right) and characteristics (up and down) |
Atomic Weight | found by averaging weights for different atoms of an atom |
Neutrons | have no charge (are neutral) |
Neils Bohr | put all the information together and developed the Bohr model |
Definition of a Molecule | the smallest combination of 1 or more atoms that are strongly bonded in a specific way |
Electrons | have a negative charge |
Where are the protons located? | in the center |
where are the neutrons located? | in the center |
where are the electrons located? | on the orbitals |
what elements are man-made? | 93+ |
how are molecules different then elements? | they can be composed of more than one atom |
Where does the word chemistry come from? | the Arabic words for Egyptian Art |
Who was the first person to use the word, "atom"? | Democritus, as a way to describe something that can not be broken down any further |
How small is an atom? | It would take 50 million atoms to = 1 cm if they could be lined up side by side |
How small are electrons? | 1,837 electrons would equal the weight of one proton |
How many protons does a atom have vs. electrons? | it is an equal amount |
How many elements were there in the mid to late 1800s? | there were around 30 elements |
How do you make a solid? | By freezing a liquid |
How do you make a liquid? | By heating a solid |
How do you make a gas? | By boiling the liquid |