Solution: Product Placement
Answer: BASE ATTRIBUTES

Written by Sara Goodchild

Acrosses are entered normally. Downs are given in alpha order of answers.

As suggested by the flavourtext, half of the Downs (14 answers) can be entered normally. The first letters of the clues for the unchanged Downs give "4 reaction types." That phrase, along with the chemistry theme in the clues and flavourtext, should suggest the 4 main types of chemical reactions as set out in North American high school chemistry classes: synthesis, decomposition, single replacement, and double replacement. (For those from other education systems, Googling for “4 reaction types” can also lead to this aha.) The patterns associated with these chemical reaction types suggest how to modify the remaining Downs.

Classify the “products” based on how they were formed and read the circled letters in each group left to right to give the final answer, BASE ATTRIBUTES.

Reaction type Reactions Circled letters
Synthesis REGRET + TABLE → REGRETTA[B]LE
LEVI + TATE → LEVIT[A]TE
BA
Decomposition MISSPOKE → MI[S]S + POK[E]
SOFTWARE → W[A]RE + SOF[T]
SEAT
Single replacement BURT → YUR[T]; BAKER → [R]AKER
HIPS → R[I]PS; VISIBLE -> RISI[B]LE
TRIB
Double replacement SQUARE + FLASH → SQ[U]ASH + FLAR[E]
BITING + MASON → MA[T]ING + BI[S]ON
UTES

ACROSS

Wordplay Entry
1. CHE(m) + APER CHEAPER
6. anag. SCLERA
10. A’S + TRO(d) ASTRO
13. ACHES inside anag. ERIN (“painstakingly”) REACHES IN
17. MUS< + KEGS MUSKEGS
18. CAP< + IF + I + C PACIFIC
19. YEAR(n) YEAR
20. EAR + L EARL
21. anag. USURPERS
22. B + EAGLE BEAGLE
23. H(e)R + O inside TATS THROATS
25. S(ART)R + E SARTRE
27. (STRAT + A)< STRATA
29. OR + LE + ANS ORLEANS
31. CHEM(ical) in SA SCHEMA
33. F(amily) in PERGOLA anag. LEAPFROG
37. LAB anag. + Y ABLY
38. “el” ELLE
40. BRIT + sTiLlEd BRITTLE
41. anag. EDWARD I
44. R(I + SINGS)UN RISING SUN
45. REP(R)O REPRO
46. TO(BAG)O TOBAGO
47. anag. PRESS ON

DOWN

Wordplay Entry
Swap last two letters in ALLELES ALL ELSE
BREAK anag. BAKER
BAR + BAR + DEANE anag. BARBARA EDEN
B(IT)ING BITING
BRUTAL – al; anag. BURT
Swap two letters in CLAMS CALMS
CHIC + LE(t) CHICLE
(voi)D(ing) + PAY anag. + ASS DAY PASS
(b)ETAS ETAS
(PUCE + YE)< EYECUP
F + La + S + H FLASH
H + IPS HIPS
hidden LEVI
anag. MASON
anag. MISSPOKE
N + ODDER NODDER
“rising sun” = SUN< containing CLUE anag. NUCLEUS
O + ESTER anag. + IA ORESTEIA
anag. RARE
Re(G)Re + T REGRET
R(E)ISER REISER
PRO< inside SCIO(n) SCORPIO
F inside SWORE AT anag. SOFTWARE
SQU(I->A)RE SQUARE
TA(B)LE TABLE
T(ASK)BAR TASKBAR
Ta + Te TATE
V + I + S + I + BLE(d) VISIBLE