Question

Calculate the mass ratio of a bromine atom to an atom of (a) neon (b) calcium (c) helium

Short answer

Answer: The approximate mass ratios are as follows: (a) Bromine to Neon: 3.95 (b) Bromine to Calcium: 1.99 (c) Bromine to Helium: 19.98

Step-by-step solution

Identify the atomic masses of the elements

Using the periodic table, we can find the atomic masses of the elements involved. Bromine (Br) has an atomic mass of approximately 79.9, neon (Ne) has an atomic mass of approximately 20.2, calcium (Ca) has an atomic mass of approximately 40.1, and helium (He) has an atomic mass of 4.0.

Calculate the mass ratio of bromine to neon

Divide the atomic mass of bromine (79.9) by the atomic mass of neon (20.2) to find the mass ratio: Bromine to Neon mass ratio = \(\frac{79.9}{20.2}\) = 3.95 (approximately)

Calculate the mass ratio of bromine to calcium

Divide the atomic mass of bromine (79.9) by the atomic mass of calcium (40.1) to find the mass ratio: Bromine to Calcium mass ratio = \(\frac{79.9}{40.1}\) = 1.99 (approximately)

Calculate the mass ratio of bromine to helium

Divide the atomic mass of bromine (79.9) by the atomic mass of helium (4.0) to find the mass ratio: Bromine to Helium mass ratio = \(\frac{79.9}{4.0}\) = 19.98 (approximately) So, the mass ratios are as follows: (a) Bromine to Neon: 3.95 (approximately) (b) Bromine to Calcium: 1.99 (approximately) (c) Bromine to Helium: 19.98 (approximately)

Key concepts

Atomic Mass

Atomic mass is a fundamental concept in chemistry that refers to the mass of an atom. It is typically measured in atomic mass units (amu), where one amu is defined as one twelfth of the mass of a carbon-12 atom, which is approximately equal to 1.66 x 10^-24 grams. This measurement allows scientists to compare the relative masses of different atoms in a quantifiable manner.

An element's atomic mass can be found on the periodic table, and it takes into account the natural abundance of its isotopes. Isotopes are atoms of the same element that have different numbers of neutrons. Because isotopes have varying masses, atomic mass is a weighted average that reflects these differences, providing a more accurate representation of an element's mass as it occurs naturally.

To calculate atomic mass, consider the atomic masses of each isotope multiplied by their relative abundance (as a decimal), then sum these values. Understanding atomic mass is essential as it aids in calculating the mass ratios between different elements, which is a common requirement in chemistry homework and labs.

Elements

Elements are pure substances that consist of only one type of atom. They are the basic building blocks of matter and cannot be broken down into simpler substances by chemical means. Each element is defined by the number of protons in its nucleus, known as its atomic number. For example, hydrogen has an atomic number of 1, which means it has one proton.

• Each element may exist in different forms, called isotopes, based on the number of neutrons present in its nucleus.
• Elements are represented by unique chemical symbols, usually derived from their English or Latin names; for instance, the symbol for bromine is Br.
• The properties of an element are unique, which influences how it reacts with other substances.

When we talk about elements in exercises like the mass ratio calculation, we deal with their atomic masses to determine how they compare in terms of size and mass. Understanding elements and their isotopic forms help us make predictions about chemical reactions and the formation of compounds.

Periodic Table

The periodic table is a powerful tool in chemistry that organizes all known elements in a structured way based on their atomic number, electron configurations, and recurring chemical properties. This arrangement allows for easy comparison and study of elements’ properties and relationships.

Each horizontal row on the periodic table is called a "period," and each vertical column is called a "group" or "family." Elements in the same group typically exhibit similar chemical and physical properties due to having similar valence electron arrangements.

The periodic table is essential for calculating mass ratios in chemistry exercises because it provides the atomic masses of elements at a glance. For instance, finding the atomic mass of bromine, neon, calcium, and helium in order to calculate their mass ratios requires looking them up on the periodic table.

• Elements in the periodic table are arranged so properties recur periodically, a pattern known as periodicity.
• Groups, such as the noble gases or alkali metals, often share significant chemical characteristics.
• Understanding the layout enhances comprehension of chemical reactivity and trends across periods and groups.

The table is an indispensable resource for students and chemists alike, facilitating deeper insights into the building blocks of matter.