Chapter 6 Science
A carbon atom with 6 protons, 6 electrons and 6 neutrons will have a mass number of?
12
An atom of iron with 79 protons, 79 electrons and 118 neutrons what is the mass number?
197
If the Isotope of Uranium 235 has 92 protons, how many protons does Uranium- 238 have?
92
What did Ruthford believe was in the center of an atom?
A nucleus
The smallest particle into which an element can be divided and still have the properties of that element is a
Atom
Dalton believed that....
Atoms of the same element are exactly alike
Which of the following took place in the late 1800's ?
Dalton's theory was changed
How would you describe the nucleus
Dense, postivly charged
What particles did J.J. Thomson discover?
Electron
In the Plum- pudding model of a atom, the plums represent....
Electrons
The raised surfaces are the?
Electrons
Objects are pulled by (blank)
Gravitational force
Where are electrons likely to be found?
In electron clouds
What is the meaning of the word atom?
Not able to be divied
Every atom of a given element has the same number of ....
Protons
What did Democritus, Dalton, Thomson, Bohr and Ruthford all have in common?
They each contributed to the devolpment of the atomic theory
Who Invented the plum- pudding model?
Thomson
All atoms of an element have the same (blank)
atomic number
The number of protons in an atom determines it's (blank)
atomic number
In 1803, John Dalton proposed all substances are made of (blank)
atoms
Electrons around the nucleus are held in place by (blank) force
electromagnetic
In a atom which has the least mass?
electron
20th century scientists believed electrons are found in regions called (blank)
electron clouds
Isotopes have different numbers of (blank)
electron clouds
Thomson discovered the negatively charged particles are called (blank)
electrons
The pushes and pulls between objects are called (blank)
forces
A charged particle is called a (blank)
ion
Most elements have a mixture or two or more (blank)
isotopes
The sum of the protons and neutrons in an atom is called the (blank)
mass number
Most of the atom's mass is found in the (blank)
nucleus
The region in a atom that contains most of the mass is called the (blank)
nuclues
A positivley charged particle in the nucleus of an atom is called a (blank)
proton