execute as @e[tag=boom,tag=lit] run scoreboard players add @s timer 1
execute at @e[tag=boom,tag=lit] run particle smoke ~ ~2 ~
execute at @e[tag=boom,tag=lit,scores={timer=50}] run summon tnt ~ ~ ~ {fuse:0s}
execute as @e[tag=boom,tag=lit,scores={timer=50}] run kill @s