The heat lost by the beads is equal to the heat gained by the water. The specific heat capacity of water is 4.18 joules/gram. "w" will denote water's property and "b" will denote the beads' properties.
mw x Cpw x ΔTw = -mb x Cpb x ΔTb
100 x 4.18 x (29.9 - 25) = 34.5 x Cpb x (100 - 29.9)
Cpb = 0.84 joules/gram