Group I properties
| English | Chinese | Pinyin |
|---|---|---|
| Group I | 第一族 | dì yī zú |
| alkali metals | 碱金属 | jiǎn jīn shǔ |
| reactivity | 活泼性 | huó pō xìng |
| hydroxide | 氢氧化物 | qīng yǎng huà wù |
The reactive Group I 第一族 metals
- Drop a small piece of sodium in water and it fizzes across the surface.
- The Group I metals (the alkali metals 碱金属) are soft, light and very reactive.
Group I trend lab
Follow Group I metals down the group and watch reactivity increase.
How many electrons are in the outer shell of a Group I element?
Group I elements have one outer electron.
Group I metals are soft enough to cut with a knife.
They are soft and have low densities.
Group I metals lose one electron to form ions with a charge of +______.
Losing one electron gives a +1 ion.
Properties of Group I
- They are soft (can be cut with a knife) and have low densities.
- They have one outer electron, which they readily lose to form +1 ions.
Every Group I atom has one electron in its outer shell, which is why they react in similar ways
Groups are columns and periods are rows; metals sit on the left, non-metals on the right
Going down Group I, reactivity:
The outer electron is lost more easily down the group.
Reactivity 活泼性 down the group
- Reactivity increases down Group I (lithium → sodium → potassium...).
- The outer electron is further from the nucleus, so it is lost more easily.
Group I metals react with water to form a hydroxide and:
Metal + water → metal hydroxide + hydrogen.
Reaction with water
- Group I metals react with water to form a hydroxide 氢氧化物 + hydrogen gas.
- The reaction gets more vigorous down the group.
Worked example. Lithium fizzes gently on water; sodium darts about; potassium reacts so fast it bursts into lilac flame. Reactivity clearly increases down the group.
Potassium reacts so vigorously with water that the hydrogen given off burns with a lilac flame — reactivity increases down Group I
You've got it
- Group I (alkali metals) are soft, low-density, with one outer electron (+1 ions)
- reactivity increases down the group (outer electron lost more easily)
- they react with water → metal hydroxide + hydrogen, more vigorously down the group