It's about half as heavy as a Football (American).
In other words, 7 ounces is 0.48275862068970 times the weight of a Football (American), and the weight of a Football (American) is 2.071428571428 times that amount.(a.k.a. "pigskin") (NFL standard)
Per National Football League official rules, an American football must weigh between 14 ounces and 15 ounces. Because of NFL regulations, ceremonial considerations, and backup requirements, each NFL Superbowl requires the manufacture of 144 balls exclusively for the event.
It's about two times as heavy as a Deck of Cards.
In other words, 7 ounces is 2.10 times the weight of a Deck of Cards, and the weight of a Deck of Cards is 0.480 times that amount.(ISO 216 B8 size, a.k.a. "poker size" 63 x 88 mm, 52-card deck)
A deck of 52 ISO 216 B8-size playing cards weighs 3.30 ounces. Utilizing nearly 3,700 decks, the record-holding largest card tower was built in early 2010, stood over 3.5 m (11 ft), and weighed over 8,000 ounces.
It's about half as heavy as a Football (Soccer).
In other words, 7 ounces is 0.460 times the weight of a Football (Soccer), and the weight of a Football (Soccer) is 2.20 times that amount.(a.k.a. Soccer, a.k.a. Association Football) (FIFA Law 2 specification)
According to FIFA's Law of the Game number 2, a football must weigh between 14 ounces and 16 ounces. An artifact on display at the Smith Art Gallery in Museum in Stirling, Scotland is said to be the world's oldest football and is about one-third to one-half the size of a modern football.
It's about three times as heavy as a Battery (C).
In other words, 7 ounces is 3.10 times the weight of a Battery (C), and the weight of a Battery (C) is 0.320 times that amount.(Alkaline)
A "C" size battery weighs 2.30 ounces. C batteries are typically used in medium-drain devices such as musical instruments.
It's about one-third as heavy as a Basketball.
In other words, 7 ounces is 0.318181818180 times the weight of a Basketball, and the weight of a Basketball is 3.14285714290 times that amount.(NBA official ball standards, Size 7)
A regulation NBA basketball, manufactured by Spalding, is known as a Size 7 ball and weighs 22 ounces. These balls have 4,118 pebbles each with a diameter of 2.5 mm
It's about three-and-a-half times as heavy as a Tennis Ball.
In other words, 7 ounces is 3.440 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 0.2910 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 2.04 ounces. Competition balls are also tested for bounce height, with the standards requiring that a ball dropped from 254 cm must bounce back to a height of 135 cm to 147 cm.
It's about four-and-a-half times as heavy as a Golf Ball.
In other words, 7 ounces is 4.3210 times the weight of a Golf Ball, and the weight of a Golf Ball is 0.23140 times that amount.(per R&A USGA Rules of Golf; maximum rule weight)
According to the Rules of Golf (as approved by the United States Golf Association and the Rules Committee of the Royal and Ancient Golf Club of Saint Andrews), golf balls must weigh no more than 1.620 ounces. Golf balls are not required to have the familiar dimpled pattern, but the design has been popular since its invention in 1905 because it reduces drag while increasing lift.