Question

1. Of the physical changes listed below, which one absorbs energy?

		sublimation
		condensing
		freezing
		deposition 2. As a solid melts to form a liquid, its temperature increases. True False 3. Which term below best describes the element americium, Am? nonmetal transition metal inner transition metal halogen 4. Consider the Lewis symbol for nitrogen. How many single (i.e. unpaired) electrons are on this atom? 2 4 1 3

Answer 1

1)

sublimation is change from solid to gas.

It will require energy

condensation is change from gas to liquid and it gives energy

freezing is change from liquid to solid and it gives energy

deposition also gives energy

So, Answer is sublimation

2)

melting occurs at a constant temperature.

For example, ice changes to water at 0 oC. Temperature doesn’t change here

Answer: false

3)

Am is a f block element. f block elements are also known as inner transition metals

Answer: inner transition metals

4)

Number of electron in N = 7

Electronic configuration is 1s2 2s2 2p3

Noble gas having lesser electron than N and closest to it is Helium (He)

Number of electron in He = 2

electronic configuration of He is: 1s2

So, electronic configuration of N in noble gas form is: [He] 2s2 2p3

3 electrons in P orbital will occupy 3 different p orbitals.

So, all these 3 electrons will be unpaired

Answer: 3