Atomic Structure Flashcards Preview

Chemistry Module 4 > Atomic Structure > Flashcards

Flashcards in Atomic Structure Deck (17):

What charge is a nucleus, electron and an atom?

Nucleus - positively charged
Electron - negatively charged
Atom - neutral


What is the atomic number?

Number of protons in an atom


What is the mass number?

The total number of protons and neutrons in an atom


Explain why a substance is an element?

Because it cannot be broken down chemically and contains only one type of atom


Describe the main stages in the development of atomic structure illustrating the provisional nature of evidence

- Dalton's atomic theory
- J.J. Thompson (discovery of the electron)
- Rutherford (nuclear atom)
- Bohr (electron orbits)


What is a nucleus made from?

Protons and neutrons


Recall the relative charge and relative mass of an electron, a proton and a neutron

- electron charge -1 and mass 0.005 (0)
- proton charge +1 and mass 1
- neutron charge 0 and mass 1


Describe isotopes

Varieties of an element that have the same atomic number but different mass numbers


Describe the arrangement of elements in the Periodic Table

- Columns are called groups, rows are called periods
- elements in the same group have the same number if electrons in the highest occupied energy level (outer shell)


Explain the identity of an element can be deduced from its electronic structure

1. Find the element in the periodic table. Work out which period it is in, and draw that number of circles around the nucleus
2. Work out which group the element is in and draw that number of electrons in the outer circle
3. Fill the other circles with electrons
4. Count your electrons and check that they equal the atomic number


Describe Dalton's atomic theory snd how the work or J.J.Thompson, Rutherford and Bohr contributed to the development of the theory of atomic structure

- the theory changed as new evidence was found
- science explanations are provisional but more convincing when predictions are later confirmed


Explain why an atom is neutral in terms of its sub-atomic particles

Atoms contain 3 sub-atomic particles, the number of electrons in an atom is always the same as the number of protons, so atoms are electrically neutral overall.


What is the radius and mass of an atom?

Radius -10⁻¹⁰m
Mass - 10⁻²³g


Identify isotopes from data about the number of electrons, protons and neutrons in particles

Isotopes have the same atomic number but a different mass number


Deduce the electronic stricture of the first 20 elements in the periodic table


Explain the significance of the work of Dalton, J.J. Thompson, Rutherford and Bohr in the development of the theory of atomic structure

- unexpected results (e.g, Geiger and Marsden's experiment) led to the theory of a nuclear atom


What does an atom have?

A nucleus surrounded by electrons