1.2. Atomic structure - periodic table
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
Elements in the same group react ______________
Similarily
How did Mendeleev organize his periodic table?
in order of increasing atomic mass
Why were there gaps in mendeleevs periodic table
for undiscovered elements
Why was Mendeleev’s periodic table accepted?
it had gaps for undiscovered elements and grouped elements together by similar properties
Why was mendeleevs periodic table inaccurate
Isotopes weren’t discovered so mendeleev made no provisions for them on the table
Definition of a metal in terms of the periodic table
Elements that react to lose electrons and form positive ions
For metals, the further down a group you go what happens to the reactivity and why
Increases because there are more electron shells so there is a weaker force of attraction between the nucleus and outermost electrons- so electrons are lost more easily and the atoms react more easily
For non-metals the further down a group you go what happens to the reactivity and why
Decreases because they have to gain an electron - there is a weak force of attraction between the nucleus and the electrons when going down the group, and so it is harder to gain electrons, making reacting harder
Metal properties (6)
good conductors of heat and electricity, malleable, solid at room temp, ductile, shiny, high boiling point and melting point
Why are noble gases unreactive?
They have a full outer shell
Why are noble gases useful in applications
They are chemically inert
does the boiling points of noble gases increase or decrease going down the group
melting and boiling points increase going down the group
What do group 1 metals form when reacted with water
Alkaline solutions
Alkali metal properties
Soft, low densities, low melting points, very reactive
What happens to softness going down the alkali metals group
Get softer
What happens to the melting points going down the alkali metals group
Decrease
Lithium + water
Lithium hydroxide + hydrogen
Sodium + water
Sodium hydroxide + hydrogen
Potassium + water
Potassium hydroxide + hydrogen
Observations of lithium reacting with water
-fizzing -lithium floats and then disappears
Observations of sodium reacting with water
-more vigorous fizzing -moves rapidly on surface of water -dissolves quickly
Obeservations of potassium reacting with water
-reacts more vigorously than sodium -burns with lilac flame -moves very rapidly on surface of water -dissolves very quickly
halogen atoms are d_________
diatonic
diatonic meaning
form molecules made of pairs of atoms