How many chest compressions should be given before rescue breaths?

If you're well-trained and confident in your ability, check to see if there is a pulse and breathing. If there is no breathing or a pulse within 10 seconds, begin chest compressions. Start CPR with 30 chest compressions before giving two rescue breaths.

Explanation:

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If you're well-trained and confident in your ability, check to see if there is a pulse and breathing. If there is no breathing or a pulse within 10 seconds, begin chest compressions. Start CPR with 30 chest compressions before giving two rescue breaths..

Explanation:

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.