(DONE) Chapter 5 - Lecture 4

Question 1

law of definite proportions

Answer 1

• A given compound always contains the same proportion by mass of the elements

Question 2

Nucleus (2)

Answer 2

• Dense centre of positive charge surrounded by moving electrons.
• Contains protons and neutrons

Question 3

Protons (3)

Answer 3

• positive charge; found in nucleus
• same magnitude of charge as the electron (e- )
• much greater mass than an electron (~1800 x mass of e- )

Question 4

neutrons (4)

Answer 4

• Neutral particles in the nuclei
• Slightly larger mass than a proton but no charge
• Neutrons and protons collectively called nucleons
• Some elements can have atoms with different numbers of neutrons

Question 5

Daltons atomic theory (2)

Answer 5

• All atoms of the same element contain the same number of protons and electrons BUT atoms of a given element may have different numbers of neutrons
• All atoms of a given element are similar to one another

Question 6

atomic number (3)

Answer 6

• characteristic of the element
• equal to the number of protons in the nucleus
• top left number of element

Question 7

mass number

Answer 7

• number of protons + number of neutrons

Question 8

isotopes

Answer 8

• atoms of the same elements with the same number of protons but different number of neutrons

Question 9

isobars

Answer 9

• atoms that have the same mass number but different atomic number (different elements)

Question 10

atomic mass units

Answer 10

• mass of 1 atom of carbon 12

- 1 amu = 1.66x10^-24 g