Topic 1 | Atomic Structure and the Periodic Table Flashcards
What is the smallest part of an element that can exist?
The smallest part of an element that can exist is an atom.
What does the chemical symbol ‘Na’ represent?
The chemical symbol ‘Na’ represents an atom of sodium.
How are compounds formed?
Compounds are formed from elements by chemical reactions, which always involve the formation of one or more new substances and often involve an energy change.
How can mixtures be separated?
Mixtures can be separated by physical processes such as filtration, crystallisation, simple distillation, fractional distillation, and chromatography. These processes do not involve chemical reactions.
What was the first model of the atom?
The first model of the atom was that atoms were tiny spheres that could not be divided.
What is the plum pudding model of the atom?
The plum pudding model describes the atom as a ball of positive charge with negative electrons embedded in it.
What did the alpha particle scattering experiment reveal?
The alpha particle scattering experiment revealed that the mass of an atom is concentrated at the centre (nucleus) and that the nucleus is positively charged.
What did Niels Bohr propose about the atom?
Niels Bohr proposed that electrons orbit the nucleus at specific distances, which was supported by experimental data.
What are the relative charges of protons, neutrons, and electrons?
Protons have a relative charge of +1, neutrons have a charge of 0, and electrons have a charge of -1.
What is the atomic number of an element?
The atomic number is the number of protons in an atom of an element. All atoms of a particular element have the same number of protons.
What are isotopes?
Isotopes are atoms of the same element with different numbers of neutrons.
How is the relative atomic mass calculated?
The relative atomic mass is calculated by taking the average mass of the isotopes of an element, weighted by their abundance.
How do electrons occupy energy levels in an atom?
Electrons occupy the lowest available energy levels (shells) closest to the nucleus. For example, sodium has 2 electrons in the first shell, 8 in the second, and 1 in the third.
How are elements arranged in the periodic table?
Elements are arranged in order of atomic (proton) number, with elements having similar properties placed in the same group (column).
What was John Newlands’ contribution to the periodic table?
John Newlands ordered elements by atomic weight and noticed that similar properties occurred every eighth element, calling this the ‘law of octaves.’
How did Mendeleev improve the periodic table?
Mendeleev ordered elements by atomic mass but left gaps for undiscovered elements and predicted their properties, which were later confirmed.
Where are metals and non-metals located on the periodic table?
Metals are found to the left and towards the bottom of the periodic table, while non-metals are found towards the right and top.
What is a characteristic property of Group 1 alkali metals?
Group 1 alkali metals have a single electron in their outer shell, making them highly reactive, especially with water, oxygen, and chlorine.
Why are noble gases unreactive?
Noble gases are unreactive because they have a full outer shell of electrons, making them stable and unlikely to form molecules.
What happens to the reactivity of halogens as you go down the group?
The reactivity of halogens decreases as you go down the group because the outer electrons are further from the nucleus and less strongly attracted.
How do transition metals compare to Group 1 metals?
Transition metals are harder, stronger, have higher melting points, and are much less reactive than Group 1 metals.
What is a characteristic of transition metal ions?
Transition metal ions can have many different charges and often form coloured compounds.
What is a common use of transition metals?
Transition metals are often used as catalysts in chemical reactions, such as iron in the Haber process.
