Answer:5
Explanation:The pnictogen group, or nitrogen group, is located in column 15 of the periodic table. This family consists of the elements nitrogen, phosphorus, arsenic, antimony, bismuth, and ununpentium (N, P, As, Sb, Bi, and Uup, respectively). Each member of this family contains five valence electrons.
Answer: 530 hours
Explanation:
The reduction of Nickel ions to nickel is shown as:
of electricity deposits 1 mole of Nickel
1 mole of Nickel weighs = 58.7 g
Given quantity = 18.0 kg = 18000 g (1kg=1000g)
58.7 g of Nickel is deposited by 193000 C of electricity
18000 g of Nickel is deposited by =
of electricity
where Q= quantity of electricity in coloumbs = 59182282.8C
I = current in amperes = 31.0 A
t= time in seconds = ?

(1h=3600 sec)

Thus 530 hours are required to plate 18.0 kg of nickel onto the cathode if the current passed through the cell is held constant at 31.0 A
Cause limestone breaks down dirt and stone
Answer:
a mixture is a material made up of two or more different substances which are physically combined.
Answer:
Dolphins use a method called echolocation to detect things such as obstacles and prey in the water. If a dolphin swimming in seawater at 25°C sends a 220-dB click with a frequency of 120.0 Hz, and then detects the reflection of the click exactly one-twentieth of a second later, approximately how far away is the object?