120 PRINT " LIGHT IS CONSIDERED BOTH A PARTICLEAND A WAVE BY PHYSICISTS. THIS THEORY IS HARD TO EXPLAIN, BUT I WILL ATTEMPT TO SHOW YOU EXACTLY HOW LIGHT IS PRO- DUCED. FIRST, YOU MUST KNOW THAT THERE ARE 3 TYPES OF BASIC ";
130 PRINT "PARTICLES INVOLVED"
140 PRINT : PRINT " THE ELECTRON, WHICH HAS A 'NEGATIVE' CHARGE;"
150 PRINT " THE PROTON, WHICH HAS A 'POSITIVE' CHARGE;"
160 PRINT " AND THE NEUTRON, WHICH HAS A NEUTRAL CHARGE"
170 PRINT : PRINT "(HIT ANY KEY)";: GET A$
180 PRINT : PRINT : PRINT : PRINT
190 IF PEEK(232) = 252 THEN 210
200 HOME : GOSUB 670: VTAB (24)
210 HGR : HCOLOR= 7
220 SCALE= 1: ROT= 0
230 DRAW 3 AT 96,73: DRAW 4 AT 106,72
240 PRINT "THIS IS THE NUCLEUS OF OUR DEMONSTRATIONATOM. IT IS COMPOSED OF 1 NEUTRON AND 1PROTON."
250 FOR K = 1 TO 6000: NEXT
260 PRINT
270 PRINT "THE ELECTRON 'ORBITS' THE NUCLEUS, BUT DOES NOT TOUCH IT.
280 W = 75:H = 5
290 FOR A = -50 TO 150 STEP H
300 X = W *( COS(A/31.42)):Y = W *( SIN(A/31.42))
310 X = X +(.2 *X)
320 X1 = W *( COS((A -H)/31.42)):Y1 = W *( SIN((A -H)/31.42))
330 X1 = X1 +(.2 *X1)
340 IF A = -50 THEN 360
350 XDRAW 2 AT 100 +X1,77 +Y1
360 DRAW 2 AT 100 +X,77 +Y
370 HPLOT 100 +X1,76 +Y1
380 NEXT A
390 IF JG = 1 THEN 570
400 PRINT "WHEN ENERGY IS ADDED TO THE ATOM, THE ELECTRON JUMPS TO AN OUTER ELECTRON 'ORBIT', OR SHELL."
410 FOR K = 1 TO 5500: NEXT : PRINT
420 PRINT "WHEN ENERGY IS TAKEN AWAY, THE ELECTRON JUMPS TO AN INNER 'ORBIT'. WHEN THIS OCCURS, A ";: FLASH : PRINT "PHOTON";: NORMAL : PRINT " OF LIGHT IS PRODUCED. WATCH CLOSELY.";
430 FOR K = 1 TO 7500: NEXT
440 XDRAW 2 AT 100 +X,77 +Y:W = W -40
450 A = -50
460 X = W *( COS(A/31.42)):Y = W *( SIN(A/31.42))
470 X = X +(.2 *X)
480 DRAW 2 AT 100 +X,77 +Y
490 GOSUB 510
500 GOTO 290
510 H1 = 3: REM ***********PHOTON
520 FOR J = 170 TO 263 STEP H1
530 DRAW 1 AT J,77
540 IF J >170 THEN XDRAW 1 AT J -H1,77
550 FOR K = 1 TO 35: NEXT K
560 NEXT : XDRAW 1 AT 263,77:JG = 1: RETURN
570 PRINT : PRINT : PRINT
580 PRINT "PHOTONS TRAVEL AT ABOUT 186,000 MILES PER SECOND, AND MANY PHOTONS PUT TOGETHER MAKE LIGHT."
590 FOR K = 1 TO 7000: NEXT
600 PRINT "DIFFERENT AMOUNTS OF ENERGY TAKEN AWAY FROM AN ATOM PRODUCE ALL THE COLORS OF THE SPECTRUM."
610 FOR K = 1 TO 7000: NEXT
620 PRINT "WHEN AN ELECTRON LOSES SO MUCH ENERGY THAT IT FALLS TO THE NUCLEUS, X-RAYS AREPRODUCED."
630 FOR K = 1 TO 7500: NEXT
640 PRINT : PRINT : PRINT
650 PRINT "DO YOU WANT TO SEE THIS DEMONSTRATION AGAIN?";: INPUT A$: IF LEFT$(A$,1) = "Y" THEN 60
