Chem for Bio Chapter 2 sec 1 and 2

What are the smallest basic units of all matter?

• molecules

• atoms

• elements

• ions

Which statement best describes an electron?

• no significant mass, remain inside the nucleus and have a negative charge

• no significant mass, found in orbits around the nucleus and have a negative charge

• mass = 1 amu, remain inside the nucleus and have a positive charge

• mass = 1 amu, found in orbits around the nucleus and have a negative charge

Which particle is found in the nucleus and has no charge?

• electron
• neutron
• proton
• atom

The number of protons in an atom is equal to the number of _ .

• neutrons

• electrons

• ions

• atomic mass

The total number of protons and neutrons in the nucleus of an atom

• Atomic Number

• Mass Number

• Atomic Theory

• Electron Cloud

An atom has an atomic number of 15 and a mass number of 31. How many protons are there in the atom?

• 15

• 31

• 16

• 47

What is the mass number of "F"?

• 9
• 18
• 17
• 19

Use the image of the block from the periodic table, to determine the number of neutrons found in an atom of Nitrogen.

• 14
• 7
• 21

• 18

Chemicals that are formed when atoms are joined together

(a)  

How many electrons does the first shell hold?

• 1

• 2

• 4

• 8