// LAB.NOTE.55Cs

ELEMENT 55.
OUR REFERENCE.

SYMBOLCs
Z55
A133
STATESTABLE
SHELL P · 1e⁻
55
Shell probe · n=6
P-shell VALENCE
1e⁻
ELECTRONS1 · max 72
SUBSHELLS6s¹
CUMULATIVE55 of 55
IONISATION3.89 eV
Lone valence electron · drives all cesium chemistry
Flame455 nm · sky-blue
Melting28.5 °C
Radius298 pm · largest
Hyperfine9.193 GHz
// Fact · 01/07
Named from Latin caesius - 'sky-blue' - for its 455 nm flame.
// PRINCIPLES.4
01
ONE_NUMBER

Every screen rolls up to take-home. Hide everything that doesn't reach it.

02
NO_UPSELL

Either it's in the product or it isn't. One price. Identical product for everyone.

03
DATA_IS_YOURS

Full export at any time. Leave with everything.

04
KEYBOARD_FIRST

Built where work happens. Resilient. Devs work this way, so we do too.

// THESIS.0001

Most freelance spreadsheets are slightly wrong,
slightly stale,
slightly out of sync.
Cesium is the one that isn't.

// STUDIO.NOTE

About Ataru

Ataru is a small software studio that builds calm, durable tools for independent operators. Cesium is its first product. The studio also takes on a short list of contract engagements each year, with a focus on clean architecture, well-tested code, and software that ages well.

The work draws from the Clean Code and software-craftsman lineage: small, readable, well-named units, tests that document behaviour, and an unhurried pace.

// ROADMAP.LIVE

Built in the open

What ships next is public. The roadmap lists what we are building now, what is queued, and what has landed - and signed-in operators vote on it and suggest what comes next.

» view the roadmap
// READY

SET YOUR REFERENCE_