C4.2 Flashcards
- What is the structure of an atom?
-a very small central positive nucleus made of protons and neutrons with electrons arranged in shells around the nucleus
- What are the relative masses of protons, neutrons and electrons?
- proton= 1
- neutron= 1
- electron= negligible
- What are the charges of protons, neutrons and electrons?
- proton= +1
- neutron= 0
- electron= -1
- What is the relationship between electrons and protons in an atom?
-in any atom the number of electrons equals the number of protons
- What is the same in all atoms of the same element?
-all the atoms of the same element have the same number of protons
- How are the elements in the Periodic Table arranged?
-in order of proton number
- What happens when some elements like lithium, sodium and potassium are heated?
-they emit distinctive flame colours
- What elements emit distinctive flame colours when heated?
-lithium, sodium, potassium
- What flame colours do lithium, sodium and potassium emit when heated?
- lithium= red flame
- sodium= orange/yellow flame
- potassium= lilac flame
- Why does light emitted from a particular element give a characteristic line spectrum?
-wavelengths of light can be recorded on a line spectrum
- What wavelengths do elements have?
-they have different wavelengths depending on their different electron arrangement
- What has the study of the spectra helped?
-the study of spectra has helped chemists to discover new elements
- What are examples of new elements discovered using the line spectrum?
- caesium and rubidium
- helium by the line spectra of the sun
- What is the discovery of some elements depended on?
- new practical techniques
- e.g. spectroscopy
- What is spectroscopy?
-the practical technique used to produce line spectrum
- How do you find the proton number from the Periodic Table?
-the bottom number
- How do you find the neutron number from the Periodic Table?
-ram (top number)= proton+ neutron
= relative atomic mass- proton number= neutron number
- How do you find the electron number from the Periodic Table?
-number of electrons= number of protons
-ram (top number)= proton+ neutron
= relative atomic mass- proton number= neutron number
- What is the electron arrangement in an atom?
2.8.8
- What happens to the shell of an atom across a period?
-a shell (or energy level) fills with electrons across a period
- What is an energy level of an atom?
-a shell of an atom
- What significant does the number of electron in an elements outer shell have?
-it relates to their group number
- What are the chemical properties of an element are determined by?
-its electron arrangement
