Chemistry Chapter 2 Connect
A molecule is an independent structure composed of two or more atoms chemically ______ together. A molecule composed of two atoms of the same element is called a ________ molecule.
Bonded, diatomic
Which of the following options correctly describe the results of the experiments performed by Thomson and Millikan? Select all that apply.
Millikan measured the electrical charge of oil droplets. Millikan's work allowed the charge of the electron to be calculated. Thomson studied the behavior of cathode rays.
Which of the following statements correctly describe the observations that led to the development of the nuclear model of the atom? Select all that apply.
Rutherford determined that the main mass of the atom is concentrated in a central region. The discovery of cathode rays led to an understanding that the atom contains smaller particles. Thomson measured the mass/charge ratio for an electron.
During a chemical reaction, the total _____ of the substances present does not change. The number of substances may change, but the total amount of matter present _____.
mass; remains unchanged
Each element in a given compound comprises a fixed fraction or percent by of the compound. This observation is summarized by the law of definite .
mass, proportion
The _____ number of an atom is equal to the sum of the protons and _____ in the nucleus of the atom.
mass; neutrons
Which of the following statements correctly describe compounds? Select all that apply.
A compound contains a fixed number of atoms in its formula. A compound has a fixed mass ratio of its components.
How does Dalton's atomic theory account for the fact that different samples of the same compound always contain a fixed mass percentage of its component elements?
A given compound always contains a fixed ratio of its component elements.
Which of the following statements correctly describe a mixture? Select all that apply.
A mixture can vary in its composition. A mixture is not considered a pure substance. A mixture may contain both elements and compounds.
Which of the following statements correctly defines a molecule?
A molecule is an independent structure consisting of two or more atoms covalently bonded together.
Which of the following options correctly describe the mass number of an element? Select all that apply.
The mass number of an element is given the symbol A. The mass number is given by the sum of the protons and neutrons in the nucleus. The mass number is often written as a left superscript next to the atomic symbol.
Which of the following options correctly describe the mass number of an element? Select all that apply.
The mass number of an element is given the symbol A. The mass number is often written as a left superscript next to the atomic symbol. The mass number is given by the sum of the protons and neutrons in the nucleus.
Which of the following correctly describe atomic structure? Select all that apply.
The nucleus comprises a very small fraction of the total volume of the atom. The number of protons equals the number of electrons in a neutral atom. The protons and neutrons together comprise most of the mass of the atom.
Thomson's experiments with cathode rays determined that atoms contained even smaller particles called _____, which have a _____ charge.
electrons; negative
A compound consists of two or more different __________that are chemically bonded together in fixed proportions. A compound can be broken down into simpler substances, a process that involves a(n) ___________change.
elements, chemical
In a given chemical compound, the component _____ are present in _____ proportions by mass, regardless of the source of the compound.
elements; fixed
Rutherford's famous experiment involved bombarding a piece of foil with particles, which were known to be heavy and positively charged. The pathway of these particles was tracked by allowing them to strike a zinc-sulfide screen after interacting with the foil.
gold, alpha
The atomic mass unit _______.
is often abbreviated as amu is based on the mass of an atom of C612
An element is the simplest form of matter that has unique and chemical properties. An element consists of only one kind of .
physical, atom
It is possible for two elements to combine in different ways to form two or more different compounds, such as CO and CO2. When this occurs, the different masses of element B that combine with a fixed mass of element A can be
ratio, whole, multiple
The law of multiple proportions states that if two elements A and B combine to form two compounds, the different masses of B that combine with a fixed mass of A are ______.
the ratio of small whole numbers
A mixture contains _____ or more different substances. A mixture is NOT a pure substance, and its components can be separated by _____ means.
two; physical
