Answers:
What is a public good?
A public good is a product or service that one consumer cannot prevent another consumer from using, and is accessible without payment.
What is a negative externality?
Negative externalities occur when the social cost of a good or service is higher than the private cost.
What is a positive externality?
Positive externalities occur when there is both a social benefit and private benefit from a good or service.
What does excludability mean for goods and services?
An excludable good or service's availability is dependent on payment.
Why does the government need to handle market failures?
The natural forces of a free market do not tend to fix market failures.
Hope this helps! Have a wonderful day! :)