1.2a Periodic Table And Atoms

What is the electron arrangement for the first 20 elements?

The first energy level holds 2 electrons, the second holds 8, the third holds 8, and the fourth holds 8. This is known as the octet rule.

What are the components of an atom?

Atoms consist of a nucleus containing protons (positive charge) and neutrons (neutral), with electrons (negative charge) orbiting around the nucleus.

What does the atomic number represent?

The atomic number represents the number of protons in an atom.

What is the mass number?

The mass number is the sum of protons and neutrons in an atom.

What are isotopes?

Isotopes are variants of the same element that have the same atomic number but different mass numbers due to varying numbers of neutrons.

What is relative atomic mass (RAM)?

Relative atomic mass is the weighted average of the masses of an element's isotopes.

How can you calculate the mass number of an element?

The mass number can be calculated by adding the number of protons and neutrons in the nucleus of the atom.

What is the charge of a proton?

A proton has a positive charge.

What is the charge of an electron?

An electron has a negative charge.

What is the charge of a neutron?

A neutron has no charge (it is neutral).

Why is an atom neutral?

An atom is neutral because it has an equal number of protons (positive charge) and electrons (negative charge), which balance each other out.

How do you calculate the number of neutrons in an element?

The number of neutrons can be calculated by subtracting the atomic number (number of protons) from the mass number.

How many electrons can fit in the first shell?

The first shell can hold 2 electrons.

How many electrons can fit in the second shell?

The second shell can hold 8 electrons.

How many electrons can fit in the third shell?

The third shell can hold 8 electrons.

What is the atomic number of sodium?

The atomic number of sodium is 11.

What charge does the nucleus of an atom have?

The nucleus of an atom has a positive charge due to the presence of protons.

What is the structure of the Periodic Table?

The Periodic Table is organized by increasing atomic number, with metals on the left and non-metals on the right.

What are group 1 elements known as?

Group 1 elements are known as alkali metals.

What are group 7 elements known as?

Group 7 elements are known as halogens.

What are group 0/8 elements known as?

Group 0/8 elements are known as noble gases.

Are group 1 elements reactive or unreactive?

Group 1 elements are reactive due to their tendency to lose one electron to achieve a stable electron configuration.