Is the word ativas the same in Brazilian and European Portuguese?

Yes.

The word ativas is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only difference lies in pronunciation. Brazilian Portuguese is a syllable-timed language, where vowels tend to be more open and clearly articulated. In contrast, Continental Portuguese is more stress-timed, meaning unstressed vowels (like the first 'a' in ativas) are often "reduced," becoming much shorter, more closed, or nearly silent to the ear.

Brazilian Portuguese Examples

1. As meninas são muito ativas no esporte. (The girls are very active in sports.)
2. As redes sociais estão muito ativas hoje. (Social media is very active today.)
3. As contas ativas foram verificadas pelo banco. (The active accounts were verified by the bank.)
4. As equipes ativas ganharam o prêmio. (The active teams won the prize.)
5. As medidas ativas são necessárias para o projeto. (Active measures are necessary for the project.)

Continental Portuguese Examples

1. As raparigas são muito ativas no desporto. (The girls are very active in sports.)
2. As redes sociais estão muito ativas hoje. (Social media is very active today.)
3. As contas ativas foram verificadas pelo banco. (The active accounts were verified by the bank.)
4. As equipas ativas ganharam o prémio. (The active teams won the prize.)
5. As medidas ativas são necessárias para o projeto. (Active measures are necessary for the project.)