Question

Fill in the blanks in the table (one column per element). Symbol \(\quad$$58 \mathrm{Ni}$$\quad$$^{86} \mathrm{Kr}$$\quad\)____\(\quad\)____ Number of protons _____ \(\quad\)_____\(\quad\) 78 \(\quad\)____ Number of neutrons _____ \(\quad\)_____\(\quad\) 117\(\quad\)46 Number of electrons in the neutral atom _____ \(\quad\)_____\(\quad\)_____\(\quad\)35 Name of element_____ \(\quad\)_____\(\quad\)_____\(\quad\)____

Short answer

58Ni: Ni, 28 protons, 30 neutrons, 28 electrons; 86Kr: Kr, 36 protons, 50 neutrons, 36 electrons; Pt: Platinum, 78 protons, 117 neutrons, 78 electrons; Br: Bromine, 35 protons, 46 neutrons.

Step-by-step solution

Identify Known Data

Given the symbols **58Ni** and **86Kr**, identify that **58Ni** refers to Nickel with atomic number 28 (found on the periodic table) and **86Kr** refers to Krypton with atomic number 36. Also, from the blanks, we know another element with atomic number 78.

Fill Elemental Details for Ni and Kr

For **58Ni** (Nickel): - Atomic number (protons) = 28 - Neutrons = Mass number - Protons = 58 - 28 = 30 - Electrons = Protons = 28 (since it's neutral) - Fill the name as Nickel. For **86Kr** (Krypton): - Atomic number (protons) = 36 - Neutrons = Mass number - Protons = 86 - 36 = 50 - Electrons = Protons = 36 (since it's neutral) - Fill the name as Krypton.

Identify Unknown Element with Protons = 78

Looking up atomic number 78 on the periodic table, we find the element is **Platinum (Pt)**. Fill the symbol and name as Platinum.

Fill Missing Values for Platinum

For **Platinum (Pt)**: - Protons = 78 - Neutrons = 117 (given) - Electrons = Protons = 78 (since it's neutral) - Mass number = Protons + Neutrons = 78 + 117 = 195

Identify Element with 35 Electrons

Since a neutral atom has equal protons and electrons, look up atomic number 35 on the periodic table. - Element = Bromine (Br) - Fill the symbol and name as Bromine.

Fill for Bromine

For **Bromine (Br)**: - Protons = Electrons = 35 - Neutrons = 46 (given) - Mass number = Protons + Neutrons = 35 + 46 = 81

Key concepts

Isotopes

Isotopes are variations of the same chemical element that have identical atomic numbers (number of protons) but different mass numbers due to variations in the number of neutrons. This means that while isotopes share the same properties as determined by their atomic number, they have different mass and nuclear properties. An example to consider is Nickel, which might appear as different isotopes, like the **58Ni**. All the isotopes of Nickel would contain 28 protons, but the number of neutrons would vary, leading to different mass numbers. Think of isotopes as different flavors of an ice cream - they all share an essential base, with different toppings leading to varied appearances and weights. These differences, though subtle, can be crucial in applications like radioactive dating, medical diagnostics, and studying environmental conditions.

Atomic Number

The atomic number, typically found above the element symbol on the periodic table, represents the number of protons present in the nucleus of an atom. This number determines the chemical identity of the element, as each element has a unique atomic number. For instance, Nickel has an atomic number of 28, meaning every atom of Nickel contains 28 protons. Similarly, Platinum has an atomic number of 78, signifying that each atom of Platinum has 78 protons. This number also matches the number of electrons in a neutral atom, which is critical to an element's chemical properties, as these electrons partake in bond formation.

Mass Number

The mass number of an element is the total number of protons and neutrons in its nucleus. It provides a measure of the atom's mass and is especially important when distinguishing between different isotopes of the same element. For example, **58Ni** has a mass number of 58, composed of 28 protons and 30 neutrons. Mass numbers are always whole numbers and give us an idea about the isotope's heaviness. To find the mass number, simply add together the number of protons (atomic number) and neutrons in the nucleus. It's important to remember that electrons have negligible mass and are not considered in the mass number.

Periodic Table

The periodic table is a comprehensive chart that organizes all known chemical elements based on their atomic number, electron configurations, and recurring chemical properties. Each element is placed in a specific location due to its atomic number, and similar properties align vertically in columns known as "groups". For example, by referencing the periodic table, we can identify that an element with atomic number 35 is Bromine (Br). The table allows scientists and students alike to predict the behavior of elements, their reactivity, states at room temperature, and more. Understanding how to read the periodic table empowers anyone studying chemistry to easily categorize and anticipate the nature of elements and their interactions.