year 9 Science Homework Week 3 - Naomi Arthur | Biblioteka

1

Who developed the atomic model adding that electrons orbit the nucleus at specific distance?

Rutherford

Chadwick

Bohr

1

What is the maximum number of electrons in the first shell?

1

2

8

1

What is the maximum number of electrons in the second shell?

1

2

8

1

Magnesium has 12 electrons. How many electrons will magnesium have in its 1stshell?

2

8

12

1

Magnesium has 12 electrons. How many electrons will magnesium have in its 2nd shell?

2

8

12

1

Magnesium has 12 electrons. How many electrons will magnesium have in its 3rd shell?

2

8

12

1

What do carbon-12, carbon-13 and carbon-14 all have in common?

Same number of neutrons

Same number of protons

Different number of protons

1

What is different about carbon-12, carbon-13 and carbon-14?

Number of protons

Number of neutrons

Number of electrons

1

An isotope is…

a version of an element with the same number of protons and neutrons but a different number of electrons.

a version of an element with the same number of neutrons and electrons but a different number of protons.

a version of an element with the same number of protons and electrons but a different number of neutrons.

1

How will adding neutrons to carbon-12 change it?

Change the atomic number

Change the element

Change the mass number

1

What is the correct calculation to find the relative atomic mass of an atom?

Relative atomic mass (Ar) = ((% × mass) + (% × mass)) / 100

Relative atomic mass (Ar) = 100 / ((% × mass) + (% × mass))

Relative atomic mass (Ar) = ((% × mass) - (% × mass)) / 100

1

What is the difference between the isotopes helium – 4, helium – 3, and helium – 5?

Number of protons

Number of neutrons

Number of electrons

1

Hydrogen-1 has 0 neutrons, hydrogen-2 has 1 neutron. How many neutrons does hydrogen-3 have?

1

2

3

1

What did scientists use to order elements by?

Atomic number

Atomic weight

Proton number

1

A.What is the correct definition on an element?

A substance composed of only one type of particle

A substance composed of only one type of atom

A substance composed of only one type of element

1

A.What is a period on the periodic table?

A horizontal row

A vertical column

A block of elements

1

What is a vertical column on the periodic table?

A period

An element

A group

1

Approximately how many elements are there?

20

50

100

1

D.What is a substance composed of only one type of atom?

atom

element

particle