A worker at a scrap metal yard had to move pieces of iron from one side of the yard to the other side of the yard using an electromagnet. After easily moving some of the smaller pieces of iron, he could not get a larger piece of iron to stay attracted to the electromagnet because it was too heavy. Since he is using an electromagnet, which of the following could he do to strengthen the electromagnet's magnetic field in order to lift the large piece of iron? Increase the electric current moving in the solenoid. O Use a smaller iron core. O Decrease the number of coils of wire in the solenoid. O He cannot change the electromagnet's strength.

1. how much energy is needed to raise the temperature of 40.0 g of argon from 25c to 40c? the specific heat capacity of argon is 0.520 j/(g·k) 2a. 23.0 ml of 0.100 m hcl (standard) are added from a buret to neutralize 50.0 ml of an unknown basic solution. 2b. if the oh- produced in the previous reaction came from ca(oh)2, then what is the molarity of the ca(oh)2? 3.calculate the new freezing-point of a solution when 60.5 grams of cacl2 solute is dissolved in 0.612 kg of water. 4. what is the maximum number of moles of alcl3 that can be produced from 5.0 mol al and 6.0 mol cl2? 5. a sample of oxygen gas has a volume of 150 ml when its pressure is 0.923 atm. if the pressure is increased to 0.987 atm and the temperature remains constant, what will the new volume be? 6. nitrogen gas in a closed container at a temperature of 100.0 oc and 3.0 atm is heated to 300 oc. what is the pressure of the gas at the higher temperature?

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

Ais not a mixture. colloid compound suspension solution