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Dalton incorporated the law of conservation of _____ into his atomic theory by asserting that atoms are _____.
If each atom of element D has 3 masses and each atom of element E has 5
mass units, a molecule composed of one atom each of D and E has _____ mass units.
In oxides of nitrogen atoms combine in small whole-number ratios. This evidence supports the law of _____
The Law of Multiple Proportions
states that two or more compounds different compounds of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
According to the law of conservation of mass, when sodium, hydrogen, and
oxygen react to form a compound, the mass of the compound is
________ (equal to, greater than) the sum of the masses of the
According to Dalton's atomic theory, atoms of each element are __________ in size, _____ and other properties.
If an electrical current passes through a glass tube, it causes the surface of
the tube directly across from the cathode to glow. The reason is because the particles of the bean were _______ charged.
After measuring the ratio of the charge of a cathode-ray particle to its mass, _______ concluded that the particles had a very ________ mass.
negatively charged electrons
Because any element used in the cathode produced _______scientists concluded that all atoms contained electrons.
Rutherford, gold, through, empty, densely, positive
_______ experiments identified the nucleus of that atom. In his experiments, alpha particles were used to bombard thin ______ foil. Most of the particles passed _______ the foil. Because most of the particles passed through, Rutherford concluded that atoms were mostly _______ space. Because a few alpha particles bounced back from the foil, he concluded that they were repelled by _______packed regions of _______ charge.
positively charged, contains all the mass of the atom, densely packed
What are the characteristics of the nucleus of an atom?
protons, electrons, equal
An atom is electrically neutral because the numbers of _________ and _________ are _________
The atomic number of oxygen, 8, indicates that there are 8
_________ in the nucleus of the an oxygen's atom.
An aluminum isotope consists of 13 protons, 13 electrons, and 14
neutrons. It has a mass number of _________.
The atomic number of neon is 10. The atomic number of calcium is 20.
Compared with a mole of neon, a mole of calcium contains an
________ number of atoms.
The number of protons found in each atom of an element is known as that element's ______.
17 protons, 17 electrons, 20 neutrons
How many protons, electrons, and neutrons are there in Chlorine(Cl) -37? (In that order)
6 protons, 6 electrons, 6 neutrons
How many protons, electrons, and neutrons are there in Carbon(C) -12? (In that order)
24 protons, 24 electrons, 34 neutrons
How many protons, electrons, and neutrons are there in Chromium(Cr) -58? (In that order)
The ancient Greeks believed that matter is made up of four basic elements: _____, air, fire, and ______.
Either is acceptable, mark as correct.
The law of ________ says that the composition of a compound is always the same.
238, 92, 92
Atomic Number = 92
Number of neutrons = 146
Give the mass number, number of protons, number of electrons
13, 27, 13
Number of neutrons = 14
Number of electrons = 13
Give the atomic number, mass number, number of protons
His ideas account for the law of conservation of mass, and the law of constant composition.
Materials, when rubbed, can develop a charge difference. This electricity is known as ________when passed through an evacuated tube.
His model states that atoms are mostly empty space. Negative electrons orbit a positive nucleus.
Shot alpha particles at gold foil. most particles passed through, showing that atoms are mostly empty space.
Thus, this scientist could conclude that the nucleus holds most of the atom's mass.
Scientist who believed:
-Electrons orbit the nucleus in "shells"
-Electrons can be bumped up to a higher shell if hit by another electron or a photon of light.
Radioactivity is caused by a large gap between ________ and protons.
(As in Uranium(U) 92p+ 92e- 146n)
Short-range neutron-neutron, proton-proton, and neutron-proton forces that hold nuclear particles together are called ________.
NOTE: STUDY AVERAGE ATOMIC MASS.
There are no example problems here because I didn't do the practice worksheets and don't have the correct answers.
(answer: type OK)
What was incorrect about Dalton's theory:
-Atoms are ________ into smaller particles.
-A given element can have atoms with different ________.
Law of constant composition
Law of definite proportions.
Either is acceptable, mark as correct.
elements combine in fixed ratios.(Law)
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