Answer:
Crystal size
Explanation:
The most obvious difference between extrusive rocks and intrusive rocks is crystal size. Because extrusive rocks cool quickly, they only have time to form very small crystals such as basalt or none at all. On the other hand, intrusive rocks grow larger crystals because they take longer to cool.
Hi,
Note that the "British pound" isn't a unit of weight (lb.) but rather a unit of currency. By weight, the lb. is the same (British or American), though Brits usually use grams or kilograms rather than pounds, for weight.
The currency conversion from the British pound (£) is roughly equal to $1.22
30 °C is around the average temperature during summer
