Final answer:
To convert 1 kg to grams, you multiply by 1000. Therefore, there were 1000 grams in the apple.
Step-by-step explanation:
To convert kilograms to grams, you need to multiply the number of kilograms by 1000 because there are 1000 grams in 1 kilogram. In this case, you purchased a 1 kg apple, so to find out how many grams were in the apple, you multiply 1 kg by 1000:
1 kg x 1000 g/kg = 1000 grams
Therefore, there were 1000 grams in the apple.