# Question 10-Writing and Language: Science Practice Test for the SAT Exam

The writer wants to conclude the attached passage with an added paragraph that emphasizes how significant an achievement the Large Hadron Collider represents. Which answer choice would best accomplish this goal?

The Large Hantron Collider: A Monument to Science

How does the world’s most powerful particle accelerator chamber work its magic? The process begins with hydrogen atoms fed at a precisely controlled rate into the source chamber of a linear [6] accelerator, here their atoms are stripped of electrons, leaving their hydrogen nuclei whose protons can now be accelerated by an electric field due to their positive charges.

By the time the protons complete this initial acceleration, they are traveling at one-third the speed of light, at which point, straight acceleration is impractical. The protons are therefore divided into four groups and sent into a circular booster consisting of four rings to maximize intensity.

The booster accelerates the protons further as they repeatedly circulate around the rings, pulsed by an electric field each time they reach a certain point. Powerful electron magnets exert a force on the pulsing protons at right angles to their direction of motion, bending the particles in a circular path as they accelerate up to 91.6% of the speed of light.

The four groups of protons recombine as they exit the rings and fly into a large proton synchrotron, 628 meters in circumference, where they [7] will reach over 99.9% of the velocity of light. Because this approaches the limiting speed of light, the energy added by the pulsating electric field no longer translates into increased velocity, but manifests instead as increased mass, causing the protons to become heavier rather than go faster.

At this point, the protons are 25 times heavier than when at rest. They are now [8] channeled into the super proton synchrotron—a huge ring seven kilometers in circumference that energizes them sufficiently for their launch into the orbit of the gigantic 27 kilometer Large Hantron Collider lying deep underground.

The Large Hantron Collider, or LHC, uses ultra sophisticated kickers to synchronize incoming protons with those already circulating. The protons enter the collider’s two vacuum pipes traveling in opposite directions and get a boost of energy from a pulse electric field at each revolution until their velocity is so near the speed of light that they become 7000 times heavier than when at rest.

(1) The energy of a collision is double that of the individually opposing electrons, producing states similar to the moments immediately following the Big Bang. (2) The counter rotating proton beams crossover in four detector caverns where they can be made to collide. (3) Particle tracks from such collisions are analyzed by computers connected to detectors in an effort to gain new insights into the birth of the universe, how it evolved, what governs its behavior today and where it might be headed in the future. [9], [10]