periodic table (further) Flashcards
What is group one called in the periodic table?
alkali metals
When group 1 reacts with water what are the products?
hydroxide and hydrogen
Why do elements become more reactive down the group and what group does this apply to?
the outer electron is further from the nucleus so less tightly attracted and easier to lose, applies to group 1 alkali metals
What are the properties of a group 1 element? (4)
soft, very reactive, low melting point, make white compounds
What are the properties of a transition metal? (5)
strong, unreactive, high melting point, make colour compounds, can be used as catalysts
What is group 7 called in the periodic table?
halogens
Why do elements become less reactive down the group and what group does this apply to?
atoms get bigger so outer shell is further from the nucleus so less able to attract an extra electron, applies to group 7 halogens
What can group 7 do?
displacement reactions
Why was Newland’s periodic table not accepted?
apart from the first two rows which worked, nonmetals and metals were in the same group, 2 elements were in the same box, reactive and nonreactive elements were in the same group
What did Mendeleev keep the same from Newland’s table?
kept elements in mass order
What did Mendeleev change about Newland’s order?
put elements of similar properties in groups
Why was Mendeleevs table believable?
he left gaps for undiscovered elements and predicted their properties, when they were discovered they were accurate predictions
What order is the modern periodic table in?
proton number
What do elements in the same group have in common?
same number of electrons in outer shell and similar properties
