Please see attachment
Atom Atomic Number Mass Number
A 100 257
B 101 257
C 101 260
D 102 259
A and B
B and C
B and D
C and D
Describe at least two experiments, including the observed results, that caused the scientific community to accept changes to Dalton's original model of the atom.
Explain, in your own words, why different elements produce different colors of light when heated.
Chemical element is defined by the number of protons in the nucleus of it atoms. For example, all Carbon atoms have exactly six protons in their nuclei. All Radium atoms have exactly 88 protons in their nuclei.
Since atoms are electrically neutral, the number of protons (positive charge) must be equal to the number of electrons (negative charge) orbiting the nucleus.
The number of protons in the element's atom is the Atomic number.
This number is interchangeable with the name of the element.
However, the nucleus contains neutrons, which have no electric charge. Therefore we can change the number of neutrons in the nucleus without changing the chemical properties of the element. Hence we can have atoms of the same element that have different number of neutrons. Atoms of the same element with different number of neutrons are called isotopes of that element. For example, Carbon-12 nucleus contains 6 protons and 6 neutrons. Carbon-14 contains 6 protons (it is still carbon) but it has 8 neutrons.
Carbon-12 and Carbon-14 are isotopes of carbon.
Since neutron weigh about the same as protons, the sum of the protons and neutrons in the nucleus is the "Mass number".
Isotopes of the same element have the same atomic number (protons only) but different mass number (protons + neutrons).
In our carbon example, both Carbon-12 and Carbon-14 have atomic number of 6, but Carbon-12's mass number is 12 while Carbon-14 mass number is 14.
The atomic and mass numbers for four different atoms are given below. Which two are isotopes of the same element?
Atom Atomic Number Mass ...
The solution answers 4 questions regarding the atomic theory of matter in great detail