In Java, the valid thread states are Running, Blocked, Terminated, and Sleeping. "Running" is not a valid thread state because it's not used to describe the state of a thread in Java. A running thread is simply a thread that is currently executing its code.

The awaitTermination() method in the ExecutorService interface is used to wait for all tasks to complete after a shutdown request has been made using the shutdown() method. It blocks until all tasks have completed or the specified timeout has passed. The isTerminated() method checks if the ExecutorService has terminated but doesn't wait.

In Java, to prevent a field from being serialized, you can mark it as transient. When a field is marked as transient, it will not be included in the serialization process. The other options do not directly prevent serialization. Marking a field as final has no impact on serialization. Marking it as static means the field will be serialized. Marking it as private affects only access, not serialization.

In Java, the keyword used to call a method defined in the superclass from a subclass is super. It's commonly used to access overridden methods or constructors in the parent class.

In Java, encapsulation is the process of hiding the internal details of a class and exposing only the essential parts. It helps in maintaining the integrity of the class and prevents unauthorized access to its data. This concept is fundamental to object-oriented programming.

In JavaFX, KeyEvent is not a mouse event; it represents keyboard events. Mouse events, such as MouseEvent and MouseDragEvent, are related to mouse input. TouchEvent deals with touch input. Understanding the distinction between these event types is essential when working with JavaFX event handling.

In Java, checked exceptions (which extend the Exception class but not RuntimeException) must be explicitly handled or declared to be thrown in a method. This requirement ensures that the code handles potentially problematic situations.

Binary Search performs in O(1) time complexity when the target element is at the first index of the sorted array. In this case, it can directly access the element and return it. When the array is empty, it still performs in O(1) time complexity as there are no elements to search. In other cases, it performs in O(log n) time complexity, where 'n' is the number of elements in the array.

In Java, the switch case can be used with data types like char, long, and byte. While other data types like int, float, boolean, double, and String are commonly used in Java, they are not directly compatible with the switch case. This limitation is important to consider when using switch statements.

In a PreparedStatement, values are assigned to placeholders using the setXXX() methods, where "XXX" represents the data type (e.g., setString() for strings, setInt() for integers). This ensures proper handling of data types and helps prevent SQL injection. The other options are not valid ways to assign values to placeholders.