1: Central matter for physicists luncheon: rocks releasing hydrogen (7)
3: Hack gets brainwave to start with: ripen green veggie (7)
5: Strap, though short, has hanger's heart (5)
7: Little Digger pens sailboat drawing sheets (6,3)
10: Republican badly ires one on the way up (5)
11: Mr Stewart on the staff (3)
12: Do tell! A puzzle found in a cornfield? (5)
13: Flashlight lent, ran sporadically (7)
14: Tumultuous, so I tour around (7)
15: Girl hangs around artists' quarter for something to get tanked with? (7)
16: Hoyts odd shops abolish horse mints (7)
18: Mild oath irritates Degas (5)
19: Three kernels of copper-yellow grain (3)
20: Indian leader raising primitive bird (5)
21: Syrian mother with a part in a play (9)
22: Surpass former church leader, at first (5)
23: Spotted one delinquent leader after parole violation (7)
24: Communist air force is entertained - entertained splendidly (7)