Question

According to Rutherford's model of the atom, how many electrons would be found in each of the following atoms? a. chlorine, which has 17 protons in its nucleus b. calcium, which has 20 protons in its nucleus

Short answer

A neutral chlorine atom has 17 electrons, and a neutral calcium atom has 20 electrons.

Step-by-step solution

Understand Rutherford's Model

Rutherford's model of the atom suggests that atoms have a central nucleus, which contains protons and neutrons, surrounded by electrons in space around the nucleus. The number of electrons in a neutral atom is equal to the number of protons.

Determine the number of electrons in a chlorine atom

Chlorine has 17 protons in its nucleus. In a neutral atom, the number of electrons equals the number of protons. Therefore, a neutral chlorine atom would have 17 electrons.

Determine the number of electrons in a calcium atom

Calcium has 20 protons in its nucleus. Following the principle that the number of electrons equals the number of protons in a neutral atom, a neutral calcium atom would have 20 electrons.

Key concepts

Atomic Structure

When delving into the world of chemistry and physics, the atomic structure is a fundamental concept that lies at the core of understanding matter's composition. In the early 20th century, Ernest Rutherford proposed a model based on his experimental observations, which depicted the atom as having a central nucleus with electrons orbiting around it, much like planets around the sun.

According to Rutherford, the nucleus is the 'heart' of the atom. It's densely packed with positively charged protons and, as later discovered, neutrally charged neutrons. Electrons are negatively charged particles that move in the space around the nucleus. This arrangement is critical because the behavior of electrons governs an atom's chemical properties and its interactions with other atoms. It was a significant improvement upon previous models, providing a clearer understanding of how atomic structure influences the behavior of elements.

Protons and Electrons

Protons and electrons are the yin and yang of an atom, essential for maintaining electrical neutrality. Protons, found within the nucleus, have a positive charge; electrons, on the other hand, are located in the electron cloud surrounding the nucleus and have a negative charge. The importance of these subatomic particles cannot be overstated as their balanced charges give atoms their stability.

• Significance of Protons: The number of protons defines the identity of an element—that is, its atomic number on the Periodic Table. For example, chlorine has 17 protons, which means it's element number 17.
• Role of Electrons: Electrons, particularly those in the outermost shell, determine the chemical reactivity and bonding capacity of an atom. They are the basis for the formation of molecules and compounds.

Without a balanced number of protons and electrons, an atom would carry a net charge, leading to the formation of ions, which significantly influences the substance's properties.

Neutral Atoms

A neutral atom is one in which the number of protons and electrons are equal, resulting in no overall electric charge. Maintaining this balance is crucial for the stability of an atom in its free state. For instance, the chlorine atom, with its 17 protons, will also contain 17 electrons when it is neutral, thereby balancing the positive and negative charges.

When atoms gain or lose electrons, they become ions and are no longer neutral. This can lead to the atom behaving differently, such as engaging in ionic bonding, which is a type of chemical bonding that arises from the mutual attraction between oppositely charged ions. In the context of Rutherford's atomic model, visualizing neutral atoms requires us to picture an equal number of tiny, negatively charged electrons orbiting a positively charged nucleus, in a delicate balance to maintain the atom's overall neutrality.