The question is incomplete; the complete question is;
In the early 1900s many scientists thought that an atom consisted of a positive substance with negative charges scattered throughout the substance. Then Ernest Rutherford completed an experiment that changed the concept of an atom. His discovery led to the understanding that an atom consists mostly of empty with space with-
Protons orbiting a dense nucleus made of electrons and neutrons
Electrons orbiting a dense nucleus made of protons and neutrons
Neutrons and protons orbiting a cloud of electrons
Electrons and protons orbiting a cloud of neutrons
Answer:
Electrons orbiting a dense nucleus made of protons and neutrons
Explanation:
Rutherford established the nuclear theory of the atom by his famous experiment. In his experiment, alpha particles were used to bombard a thin gold foil and the movement of the particles was observed on a moveable zinc sulphide screen.
It was discovered from the experiment that the atom was mostly made up of empty space. The electrons orbit a dense nucleus comprising of protons and neutrons.
Answer:
Carbon atoms can form double bonds by sharing two pairs of electrons; they can also form triple bonds by sharing three pairs of electrons.
Bromine
Symbol Br
Atomic Number 35
Atomic Mass 79.904 atomic mass units
Number of Protons 35
Number of Neutrons 45
Number of Electrons 35
Melting Point -7.2° C
Boiling Point 58.78° C
Density 3.119 grams per cubic centimeter
Normal Phase Gas
Family Halogens
Period 4
Cost $4.90 per 100 grams
Answer:
Physical change
Explanation:
Chemical change is defined as the process in which new substance with different properties is formed from old substance and the process is irreversible while physical change is a reversible process and changes only physical properties of a substance.
<em>The given experiment is an example of physical change because it is just the physical act of dissolving. The metal disk is dissolving in sodium acetate and the process is exothermic and the process is reversible as well.</em>
Hence, the correct answer is "physical change".
