Final answer:
The word 'award' in the given sentence is a concrete noun, while 'happiness' is an abstract noun. 'Door' is also a concrete noun.
Step-by-step explanation:
In the sentence "He was given an award for his courage", the noun award is a concrete noun because it refers to a physical object that can be seen and touched. In contrast, an abstract noun represents a concept or idea that cannot be physically touched, such as "courage" in the same sentence. Considering the sentence "The door slammed shut", the word door is another example of a concrete noun because it denotes a physical object that can be observed and interacted with. Lastly, in the sentence "She thought that happiness was the most important thing in life", happiness is an abstract noun. It refers to a feeling or state that cannot be directly perceived by the senses, but rather, is experienced emotionally or mentally.