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21 Cards in this Set
- Front
- Back
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Matter: anything that has ___ and takes up _____.
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Matter: anything that has mass and takes up space. |
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What is an atom? |
Very small particles that make up all matter |
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List all the parts of an atom and where they are located in it. |
Proton: positively charged particle located in the nucleus Neutron: a particle with no charge or a neutral charge located in the nucleus Electron: negatively charged particle that moves in the space around the nucleus. Nucleus: a region in the center of the atom that contains most of its mass. |
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Atoms are _____ units of matter. |
Atoms are basic units of matter.
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Atoms are mostly __________. |
Atoms are mostly empty space. |
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What is the size comparison between protons, neutrons, and electrons? |
Protons and neutrons are approximately the same size, but electrons are 2,000 times smaller. |
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Most types of matter are made up of small _________ called _____. |
Most types of matter are made up of small particles called atoms. |
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Who was the first to experiment with atoms? Where was he from? |
Democritus; he was a Greek philosopher. |
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What did the first person to experiment with atoms name the atom, and what did it mean? What did he think the atom was? |
Democritus named it atoma, meaning indivisible. He thought it was a solid sphere. |
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What law did Antoine Lavoisier come up with, and what did it mean? How did he come up with it? |
Law of Conservation of Mass; the mass of the products=mass of starting materials. He heated mercury (II) and got a silvery liquid, and he weighed the two. Their weights were equal. |
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What law did Proust come up with, and what did it mean? |
Law of Definite Proportions; Any pure compound contains the same elements in the same proportions by mass. |
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Who came up with the 5 atomic principles? 1. All matter is made of _____. 2. _____ are neither _________ nor __________ in ________ reactions. 3. Atoms of different ______ combine in _______ _________ ratios. 4. Each ________ is made of a different _____. 5. The atoms of different elements have different ______ and _________. |
Dalton; 1. All matter is made of atoms. 2. Atoms are neither created nor destroyed in chemical reactions. 3. Atoms of different elements combine in whole number ratios. 4. Each element is made of a different kind of atom. 5.The atoms of different elements have different masses and properties. |
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What does an atom have an equal amount of? |
Protons and electrons. |
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What did Rutherford discover, and how? |
He discovered the positively charged proton, which has +1 charge, along with the nucleus. He learned this from his gold foil experiment where alpha particles were concentrated on gold foil, and some particles bounced unexpectedly not straight where they were aimed. It was first thought that the electrons were attached to a positively charged sphere, but in reality, the positive part of the atom, the protons, are inside of the nucleus. Also, because most particles went straight through the gold foil, it was determined that atoms are mostly empty space. |
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What did Chadwick discover, and how? |
He discovered the neutron in 1932, that has no charge. He discovered this because neutrons weren't deflected by a magnetic field. |
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What did Bohr discover, and how? |
Bohr discovered that electrons moved around the nucleus, and at first thought it was like a ball on a string, but he later realized the way electrons travel around the nucleus is fixed like the planets in the solar system. |
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What are spectral lines? |
One wavelength of light that can be seen when an excited element's light is passed through a prism. |
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What is an electron cloud? |
The area around the nucleus where you'll probably find electrons. |
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What is the axis where electrons move called? |
The energy level. |
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What did Thomson discover and how? |
He discovered electrons, and he experimented with a cathode ray by putting positive and negative charged plates on the top and the bottom of the tube. He found that the rays were attracted to the positively charged plate, so they'd have to be negative. |
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Why is Rutherford's model sometimes called the nuclear atom? |
It's because he found the nucleus. |
