What is a period 1 element?
Q: What is a period 1 element?
A: A period 1 element is an element in the first row of the periodic table.
Q: How are elements arranged in the periodic table?
A: Elements in the periodic table are arranged in rows to show repeating properties of the elements. As atomic number increases, different properties emerge. A new row begins when chemical properties repeat and elements within a group have similar properties.
Q: How many elements are there in period 1?
A: There are only two elements in period 1 - hydrogen and helium.
Q: Why is there less elements in period 1 compared to other periods?
A: This can be explained by modern theories of atomic structure which state that this period fills up the 1s orbital and follows the duet rule, meaning it only needs two electrons to complete its valence shell so can only hold two electrons both in the 1s orbital. Therefore, it can only have two elements.
Q: What does quantum physics explain about period 1?
A: Quantum physics explains why there is less elements in period 1 compared to other periods - this is because it fills up the 1s orbital and follows the duet rule, meaning it only needs two electrons to complete its valence shell so can only hold two electrons both in the 1s orbital.
Q: What does 'duet rule' mean?
A: The 'duet rule' means that a period one element only needs two electrons to complete its valence shell so can only hold two electrons both in the 1s orbital.
Q: What happens when chemical properties repeat? A: When chemical properties repeat, a new row begins on the periodic table as different properties emerge with increasing atomic number.
