No. The humerus is the bone of your upper arm.

The humerus and ulna are found in the arms

The humerus is the arm bone between the shoulder and the elbow.

Yes, the clavicle, or collarbone, is medial to the humerus, or upper arm bone.

The clavicle is medial to the humerus. The clavicle, or collarbone, is located closer to the midline of the body than the upper body of the arm is.

The thumb would be external in relation to the humerus, if the body is laid in the anatomical position.