Atoms

Atoms

counting atoms

Open Ended

Write 3 information that you know about the atoms

Multiple Select

which of the following is/are correct about the atom

• nucleus contains protons and electrons

• nucleus contains Protons and neutrons

• electrons are revolving around nucleus

• nucleus contains protons ,neutrons, and electrons

Multiple Select

Which of the following is correct about Atomic number

• it is the number of protons

• it is the number of electrons

• Atoms of different elements have different atomic numbers

• Atoms of the same element all have the same atomic number

Multiple Choice

Isotopes are

• elements with the same atomic number and same mass

• elements with different atomic number but same mass

• elements with same atomic number but different masses

Multiple Select

select the true statements about Isotopes

• Isotopes are elements with the same atomic number but different masses

• isotopes are elements with different number of protons but same number of neutrons

• isotopes are elements with Same number of protons and electrons but different number of neutrons

• elements exist as mixtures of isotopes

Multiple Choice

Mass number is

• number of protons + electrons

• number of neutrons + protons

• number of electrons only

• number of neutrons only

Open Ended

Why do you think is the mass number called so???

Multiple Choice

How many protons, electrons, and neutrons are there in an atom of chlorine-37? Use the periodic table

• 17 Protons , 17 neutrons , 20 electrons

• 17 Protons , 20 neutrons , 17 electrons

• 37 Protons , 37 neutrons , 37 electrons

• 37 Protons , 0 neutrons , 37 electrons

MAss Number

mass number = number of neutrons + number of protons

atomic number = number of protons = number of electrons

Calculate the Atomic mass

One atomic mass unit, or 1 amu, is exactly 1/12 the mass of a carbon-12 atom

The atomic mass of any atom is determined by comparing it with the mass of the carbon-12 atom

Average atomic mass is the weighted average of the atomic masses of the naturally occurring isotopes of an element

Lets Solve

•Copper consists of 69.15% copper-63, which has an atomic mass of 62.929 601 amu, and 30.85% copper-65, which has an atomic mass of 64.927 794 amu.

Multiple Choice

A student believed that she had discovered a new element and named it mythium. Analysis found it contained two isotopes. The composition of the isotopes was 19.9% of atomic mass 10.013 and 80.1% of atomic mass 11.009. What is the average atomic mass,

• 10.013

• 11.009

• 10.811

• 10.5

Relating mass to atoms

• Mole

• •The mole is the SI unit for amount of substance.

• •A mole (abbreviated mol) is the amount of a substance that contains as many particles as there are atoms in exactly 12 g of carbon-12.

• Avogadro’s Number

• Avogadro’s number—6.022 1415 × 10²³—is the number of particles in exactly one mole of a pure substance.

• Molar Mass

• The mass of one mole of a pure substance is called the molar mass of that substance measured in g/mol