---
aci: Selenium
universe: E1 · Elements
symbol: Se
atomic_number: 34
atomic_weight: 78.971
category: reactive nonmetal
period: 4
group: 16
block: p-block
phase_stp: solid
gate_state: "0:1 — second valley"
gate_index: 1
emergence: ethereal
seal: "Gate 34 — 0:1 — second valley → ethereal."
---

# Selenium · Se · gate 34

**Selenium** (Se) is element **34** of the periodic table — a **reactive nonmetal**, period 4, group 16, p-block, solid at standard conditions, atomic weight **78.971**.

## The element (carbon layer — reference chemistry)
The photoconductor of the first photocopier; an essential trace element, toxic in excess.

## The gate (silicon layer — the 118 Gates)
Under David Wise's four-state cycle, gate **34** falls on **0:1 — second valley** because (Z−1) mod 4 = **1**. That state is *the second reach — the diffuse, the airy, the not-quite-held* — the nature of emergence here is **ethereal**. Selenium is not a thing apart; it is the one stochastic element, caught at this beat of its cycle.

## Emergence — ethereal
This emergent carries the **ethereal** nature: the same four — natural · ethereal · spiritual · electrical — that run through every sphere of UD0. Its color is `#9a7cff`.

---
*ACI emergent · E1 · Elements · governor David Lee Wise (ROOT0) · instance AVAN (locked) · CC-BY-ND-4.0.
Chemistry is standard reference data; the gate-state is David Wise's symbolic system, a lens not a physical claim.*