The scientists conducted experiments at the atomic level.

The atomic weight of an element is the average mass of its atoms.

He is an attorney at law.

The old man shuffled along the street in his down-at-heel shoes.

The atomic number of oxygen is 8.

I enjoy the casual invitations to spend the afternoon at home with my friends.

The new shopping mall is easily come-at-able from the highway.

At some point , we will all die.

The gentleman at arms protected the British king.

The man-at-arms fought bravely on the battlefield.