Chemistry Atom Unit Flashcards

Questions and Answers

What is the smallest particle of an element that retains the properties of that element?

atom

What is a positively charged subatomic particle?

proton

What is a negatively charged subatomic particle?

electron

What is a subatomic particle with no charge?

neutron Signup and view all the answers

What is the central part of an atom that contains protons and neutrons?

nucleus Signup and view all the answers

The smallest particle of an element that retains the properties of that element is a(n) ____.

atom Signup and view all the answers

Dalton's atomic theory included which idea?

Atoms of the same element are always identical. Signup and view all the answers

All atoms are ____.

neutral, with the number of protons equaling the number of electrons Signup and view all the answers

The particles that are found in the nucleus of an atom are ____.

protons and neutrons Signup and view all the answers

The atomic number of an element is the total number of which particles in the nucleus?

protons Signup and view all the answers

All atoms of the same element have the same ____.

number of protons Signup and view all the answers

How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain?

50 protons, 50 electrons, 75 neutrons Signup and view all the answers

Which of the following statements is NOT true?

The nucleus of an atom has a positive charge. Signup and view all the answers

The principal quantum number indicates what property of an electron?

energy level Signup and view all the answers

What is the shape of the 3p atomic orbital?

dumbbell Signup and view all the answers

What is the maximum number of orbitals in the p sublevel?

3 Signup and view all the answers

List the number of protons, neutrons, and electrons in carbon-13.

Protons= 6 Neutrons= 7 Electrons= 6 Signup and view all the answers

Write the electron configuration for chromium.

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^4 Signup and view all the answers

Determine the number of protons in an atom of barium using the periodic table.

56 Signup and view all the answers

What observations by Rutherford led to his hypothesis about atomic structure?

He found that most particles went straight through but not all went through. Signup and view all the answers

Explain how the atoms of one element differ from those of another element.

Atoms differ because they have different amounts of protons. Signup and view all the answers

In what way are two isotopes of the same element different?

They have different numbers of neutrons. Signup and view all the answers

What does the average atomic mass of an element depend upon?

The mass and relative abundance of each isotope of that element. Signup and view all the answers

The sum of the protons and neutrons in an atom equals the ____.

mass number Signup and view all the answers

Who was the man who suggested the idea of atoms that lived from 460 B.C. to 370 B.C.?

Democritus Signup and view all the answers

Who discovered the electron?

JJ Thomson Signup and view all the answers

Who discovered the neutron?

James Chadwick Signup and view all the answers

Who discovered the proton?

Rutherford & Mosley Signup and view all the answers

What is the plum pudding model?

J.J. Thomson's model of an atom, in which electrons were thought to be randomly distributed within a positively charged cloud. Signup and view all the answers

Who is Ernest Rutherford?

Conducted the famous gold-foil experiment and concluded that most of the atom was empty space. Signup and view all the answers

Dalton's theory essentially agreed with the present atomic theory EXCEPT for the statement that

All atoms of the same element have the same mass. Signup and view all the answers

Which of the following statements is true?

Atoms of the same element may have different masses. Signup and view all the answers

Which concept in Dalton's atomic theory has been modified?

Atoms cannot be divided. Signup and view all the answers

Isotopes of each element differ in ____.

the number of neutrons in the nucleus. Signup and view all the answers

Study Notes

Atomic Structure

An atom is the smallest particle of an element that retains its properties.
Protons are positively charged subatomic particles found in the nucleus.
Electrons are negatively charged subatomic particles located in orbitals around the nucleus.
Neutrons are neutral particles, also found within the nucleus.

Nucleus

The nucleus contains protons and neutrons, and it is the central part of the atom.
The atomic number indicates the total number of protons in the nucleus.

Dalton's Atomic Theory

Dalton proposed that atoms of the same element are identical, but this idea has been modified; atoms can have different masses (isotopes).
Atoms of different elements combine in fixed ratios to form compounds.

Charge and Neutrality

Atoms are generally neutral, possessing equal numbers of protons and electrons.

Isotopes

Isotopes of the same element differ in their number of neutrons and consequently their mass numbers, while they exhibit similar chemical behavior due to having the same number of protons.

Electron Configuration

The electron configuration for an atom specifies the distribution of electrons among orbitals.
Chromium's electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴.

Discoveries in Atomic Physics

Democritus was one of the first to propose the concept of atoms.
J.J. Thomson discovered the electron and proposed the plum pudding model of the atom.
Ernest Rutherford conducted the gold-foil experiment, concluding that atoms are mostly empty space with a dense nucleus at their center.
James Chadwick discovered the neutron.

Observations and Conclusions

Rutherford's conclusions were based on observing that most alpha particles passed through the gold foil, suggesting a mostly empty atom.
The sum of protons and neutrons in an atom equals the mass number.

Key Concepts

The average atomic mass of an element depends on the mass and relative abundance of its isotopes.
It is crucial to understand the modified aspects of atomic theory, such as the divisibility of atoms and the existence of isotopes.
The maximum number of orbitals in the p sublevel is three, corresponding to its dumbbell-shaped atomic orbital.

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Description

This quiz focuses on the fundamental concepts related to atoms. It includes key terms and definitions such as atom, proton, electron, and neutron. Test your knowledge and understanding of atomic structure with these flashcards.