Is any valid address in Ethereum liable to receive payments?

Question

Suppose I have generated a valid ethereum address, there are a no of ways of doing so including using Blockcypher's Generate Address API, using light-wallet etc. So I got a valid address, Now are these addresses published on blockchain? I mean any valid address is liable to receive payments ? Or anything else like private-public key pair or anything as such is needed (I am not good at this topic) ?

If nothing else is needed and we are ready to receive a payment as soon as a valid address is generated, I have another doubt (This part is probably specific to Light Wallet).
I was following webawllet example of lightwallet. It generates a new address by clicking the show button. So I get only a valid address as output (no private key,publick key, nothing else) and I have send some ethers to it. Will it receive the ethers? How can I claim these ethers ?

Answer 1

1-the addresses are not published in the blockchain when created.

2-a valid address could be used to receive ethers

3-to control the funds belonging to an account you need to have the private key

4- read the webwallet doc it is mentioned that :

LightWallet is a HD wallet that can store your private keys encrypted in the browser to allow you to run Ethereum dapps even if you're not running a local Ethereum node. It uses BIP32 and BIP39 to generate an HD tree of addresses from a randomly generated 12-word seed.

and

The Hooked Web3 Provider is a normal HTTP Web3 provider that allows you to "hook in" an external transaction signer that can be used to sign transactions for accounts not managed by the Ethereum client (i.e., aren't managed by geth). An example transaction signer might be an external program or device that manages its own accounts and private keys. Together, the transaction signer and the web3 provider will use the Ethereum client to place signed transactions on the network.

without the private key wich was used to generate the address you could not get the ethers