1. The word 'goose' has a different vowel sound ('oo' as in 'food') compared to 'moon', 'balloon', 'poem', 'lagoon' (all have 'oo' as in 'book' or 'o' as in 'go'). Therefore, the answer is goose.
2. The word 'nose' has a silent 'e' at the end, affecting the pronunciation of 'o', while 'horse', 'sport', 'report', 'form', 'storm', 'short' have different vowel sounds or spellings. Therefore, the answer is nose.
3. The word 'snow' has a different vowel sound ('ow' as in 'go') compared to 'cloudy', 'house', 'mouse' (all have 'ou' sound) and 'brown' ('ow' as in 'now'). However, considering the 'ow' sound, 'snow' and 'brown' are similar. If we consider the 'ou' sound, 'snow' is different. Let's re-evaluate. 'cloudy', 'house', 'mouse' have the /aʊ/ sound. 'snow' has the /oʊ/ sound. 'brown' has the /aʊ/ sound. Thus, 'snow' is different. Therefore, the answer is snow.
4. The word 'grass' has a short 'a' sound, while 'bag', 'map', 'clap', 'cat', 'fantastic' have a short 'a' sound. However, 'fantastic' has a different stress pattern. Let's re-evaluate. All words have the short 'a' sound. The word 'fantastic' has a different number of syllables and stress. Therefore, the answer is fantastic.
5. The word 'dance' has a silent 'e' at the end, affecting the pronunciation of 'a', while 'talk', 'walk', 'ball', 'mall', 'wall' have different vowel sounds or spellings. Therefore, the answer is dance.