Another way to judge: Generally, 8 eggs weigh a catty, so it is about 60 grams. But when the physics book estimates it, it uses 50 grams. Now, unless it is a small egg laid by a chick, it is about 60 grams.
Eggs (big)? 1 about 60 grams? Eggs (small) 1 about 55g.
Egg yolk (large)? 1 piece18g or so? Egg yolk (small) 1 piece15g or so.
Protein (large)? 1 38g or so? Protein (small) 1 35g or so.