C# List<baseClass> - any way to store inherited classes within, too?

I am trying to create a simple "inventory" of items, much like in any RPG. I have very basic classes made, which have properties.

Anyway, I have a base class of item and inheriting from that is weapon. item has properties (name, value, weight, "important item") that are also used within weapon, but weapon has extra properties (attack, defense, speed, handedness).

I've got the following code (sorry if the readability is horrible):

static void Main(string[] args)
{   
     List<item> inventory = new List<item>();
     inventory.Add(new weapon("Souleater", 4000, 25.50f, false, 75, 30, 1.25f, 2));
                           //item--------------------------->  weapon--------->

     Console.Write("Name: {0}\nValue: {1}\nWeight: {2}\nDiscardable: {3}\nAttack: {4}\nDefense: {5}\nSpeed: {6}\nHandedness: {7}",
            inventory[0].Name, inventory[0].BValue, inventory[0].Weight, inventory[0].Discard, 
            inventory[0].Atk, inventory[0].Def, inventory[0].Speed, inventory[0].Hands);

     Console.ReadLine();
}

Basically, what I'm trying to do is add a new weapon to the inventory, but the inventory is a List<item> type. I went out on a whim hoping that, due to it's inheritance, it'd be accepted. It was, but the properties specific to weapon aren't able to be accessed:

('shopSystem.item' does not contain a definition for 'Atk' and no extension method 'Atk' accepting a first argument of type 'shopSystem.item' could be found)

So, is there any way to achieve what I was intending here? Have an "inventory" which can store item objects, as well as weapon, armour, accessory etc. objects, which inherit from item? It is also worth mentioning that I can access all of the desired properties if I declare the following:

weapon Foo = new weapon("Sword", 200, 20.00f, false, 30, 20, 1.10f, 1);

Many thanks for reading.

Here's the item and weapon classes, if anybody is interested:

class item
{
    #region Region: Item Attributes
    protected string name = "";
    protected int baseValue = 0;
    protected float weight = 0.00f;
    protected bool noDiscard = false;
    #endregion

    public item(string n, int v, float w, bool nd){
        name = n; baseValue = v; weight = w; noDiscard = nd;}

    public string Name{
        get{return name;}
        set{if(value != ""){
            name = value;}
        }//end set
    }

    public int BValue{
        get{return baseValue;}
    }

    public float Weight{
        get{return weight;}
    }

    public bool Discard{
        get{return noDiscard;}
    }
}

class weapon : item
{
    #region Region: Weapon Attributes
    private int atk = 0;
    private int def = 0;
    private float speed = 0.00f;
    private byte hands = 0;
    #endregion

    public weapon(string n, int v, float w, bool nd, int a, int d, float s, byte h) : base(n, v, w, nd){
        atk = a; def =d; speed = s; hands = h;}

    public int Atk{
        get{return atk;}
    }

    public int Def{
        get{return def;}
    }

    public float Speed{
        get{return speed;}
    }

    public byte Hands{
        get{return hands;}
    }

}