Question

1. which of the following provides evidence to support rutherfords model of the atomic nucleus?

a) radiation produced when alpha particles hit beryllium
b) plum pudding model
c) gold foil experiment
d) spectrum of colors emitted by gas

1. which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom?

a) some uncharged particles are scattered by a gold foil.
b) all positively charged particles pass straight through a gold foil.
c) all uncharged particles are attracted towards a gold foil.
d) some positively charged particles bounce back from a gold foil.

1. the table compares the masses on three unknown subatomic particles.

which particle is most likely present in the nucleus of the atom?
a) only particle p
b) only particle q
c) both particles q and r
d) both particles p and r

1. a substance is present in the gaseous state at room temperature. which of the following best explains the probable position of the substance in the periodic table?

a) it is between groups 1 to 12 because it is a metal.
b) it is between groups 13 to 18 because it is a metal.
c) it is between groups 1 to 12 because it is a non - metal.
d) it is between groups 13 to 18 because it is a non - metal.

1. which of these represent metals?

a) x, r, p, and q
b) x and q
c) x and z
d) p and l

Explanation:

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• Rutherford's gold - foil experiment showed that most alpha particles passed through the gold foil, some were deflected, and a few bounced back. This led to the nuclear model of the atom.
• The plum - pudding model (b) was Thomson's model. Radiation from alpha particles hitting beryllium (a) led to the discovery of neutrons. The spectrum of colors emitted by gas (d) is related to atomic spectra and not directly to Rutherford's nuclear model.

• In Rutherford's gold - foil experiment, when positively charged alpha particles were shot at a gold foil, some bounced back. This indicates that there is a small, dense, positively charged part (the nucleus) in the center of the atom.
• Uncharged particles (neutrons) are not relevant to showing the positive charge in the center (a and c). If all positively charged particles passed through (b), it would not suggest a dense, positively charged center.

• Protons (P) have a relative mass of approximately 1 amu and neutrons (R) have a relative mass of approximately 1 amu (0.99 amu is close to 1 amu). Electrons (Q) have a very small mass (0.00054 amu).
• The nucleus of an atom contains protons and neutrons.

Answer:

c) Gold foil experiment

23.