If a ruby is heated it — temporarily lose its color.

✅ কেন সঠিক: This is a first conditional about a real, predictable result: If + present simple, will + base verb. So: If a ruby is heated, it will temporarily lose its colour.

❌ অন্য অপশন: ‘Would’ needs a past-tense if-clause (second conditional); ‘does lose’ and ‘has lose’ are ungrammatical here.

💡 মনে রাখুন: If + present → will + V1 (real result); If + past → would + V1 (imaginary result).