Yes they can
No, A Number or chaos form cannot be destroyed by god cards expect by another number card, spells, or Trap cards.
The best ways to prevent your cards from being destroyed are with monster effects or Counter Traps. Stardust Dragon, Solemn Judgment (now limited though), Dark Bribe, and even Destruction Jammer can all save your cards from being destroyed. There are few, if any cards that specifically prevent your continuous spell cards from being destroyed, although Field Barrier saves your Field Spell cards from destruction.
Houses Likely Destroyed
If you are talking about grave yard ...... you can. But on the show the cards are basicly destroyed.
then all cards on the field are destroyed unless the union monster has an effect that says that it can be destroyed instead of the equipped monster
YES by their effect or by the card "Pyramid Of Light"
If you mean, is it destroyed when it 'levels up', then no. It is simply 'sent to the graveyard', it is not a 'destroy' effect and cards that look for or trigger from something being destroyed, will not activate.
There are 20 such cards.
The following monsters inflict damage to your opponent when destroyed. Some of these effects will depend on whether you or your opponent destroyed it and/or if it was destroyed in battle or by a card effect:AbakiEarthbound Immortal Aslla piscuBalloon LizardMecha-Dog MarronOxygeddon
Some Yu-Gi-Oh cards with the ability to remain on the field without being destroyed by battle include "Marshmallon," "Spirit Reaper," and "Stardust Dragon."
Enchantments are not indestructible in the game. They can be removed or destroyed by certain cards or effects.
The number of cards is indefinite, because you can lose many over time. But you have only one Social Security number, and it is unique to you, and never changes.