Macroscopic Atoms; big atoms
About how many different types of atoms are there?
100
When different atoms combine, what do they form?
All known substances
Properties of a substance are determined by...
The arrangement of its atoms
What is composed of atoms?
Matter
What is the smallest part of an element?
Atom
What is a molecule?
2 or more atoms joined and acting as a unit.
What are diatomic molecules?
Chemical elements that naturally possess 2 atoms.
O2 and H2 are examples of...
Diatomic molecules
Help solve problems and study nature/the basis on which a scientific inquiry is conducted.
Scientific method
What are the steps of the scientific method?
1. Observation 2. Questions3. Hypothesis 4. Experiment5. Conclusion
What is a theory?
A set of tested hypotheses that gives an overall explanation of some natural phenomenon.
A statement on how a particular phenomenon occurs.
Law
An attempt to explain why a phenomenon occurs.
Theory
A given compound always contains exactly the same proportion of elements by mass.
Law. of definite proportion
The total mass of materials isn't affected by a chemical change in those materials.
Law of Conservation of Mass
What does the law of conservation of mass state?
mass is neither created nor destroyed
What is Dalton's Atomic theory composed of? (4)
1. Each element is made up of atoms2. Atoms of given element are identical, but the atoms of different elements are different.3. Chemical compounds are formed when atoms of different elements combine.4. Chemical reactions involve changes in the way atoms are bound together without actually changing the atoms.
At the same temperature and pressure, equal volumes of different gases contain the same number of particles.
Avogadro's hypothesis
Atoms are made of a positively charged cloud. and electrons are embedded at random.
Plum Pudding Model
What are the 3 types of radioactive emission?
Gamma Rays (Y), Beta particles (B), Alpha particles (a)
What are gamma rays?
high energy light
What are beta particles?
High-speed electrons
What are alpha particles?
Positively charges and made up of 2 protons and 2 neutrons
What 4 things compose an atom?
Protons, electrons, neutrons, nucleus
What are protons?
Positively charged *equal the magnitude to electrons neg charge
What are electrons?
Negatively charged particles
What are neutrons?
No charge *Usually have the same mass as proton
What is smaller than an atom, extremely dense, and accounts for almost all of the atom's mass?
Nucleus
What has the same number of protons, but not neutrons?
Isotopes
What are ions?
Charged atoms
What are the 2 types of ions?
anions, cations
What is the charge of an atom usually?
It's usually electrically neutral, but can be assigned a charge by either removing or adding an electron.
What is a cation?
A positive ion
What is a anion?
A negative ion
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