P7- Atomic structure ☢️⚛️

Question 1

Fill in the gaps: Atoms are very small and have a radius of _ x __^-__ m

[Remember: this is about the current model of an atom!]

Answer 1

Fill in the gaps: Atoms are very small and have a radius of 1 x 10^-10m.

Question 2

In the current model of an atom, What is the basic structure of an atom?

Hint: charged, protons and _______, surrounded by… electrons

Answer 2

• a positively charged nucleus, that is composed of both: protons and neutrons. Which are surrounded by negatively charged electrons.

Question 3

• Fill in the gaps: The radius of a nucleus is less than 1/_, ___ of the radius of an atom.
• Most of the atom is concentrated in the _______.

Hint: the current model of the atom

Answer 3

• The radius of a nucleus is less than 1/10, 000 of the radius of an atom.
• Most of the atom is concentrated in the nucleus.

Question 4

In the current model of an atom where are electrons of an atom arranged?

Hint: from the nucleus

Answer 4

The electrons of an atom are arranged at different distances from the nucleus [in different energy levels]

Question 5

how can the electron arrangements of an atom change, in the current model of the atom?

Hint: absorption or release

Answer 5

• the absorption of electromagnetic radiation or by the release of electromagnetic radiation.

Question 6

What are the differences between the absorption of electromagnetic radiation and the release of electromagnetic radiation?

Hint: further way from nuclues…, higher energy____ level and vice versa.

Answer 6

• absorption= electrons moves further away from the nucleus + a to a higher energy level.
• release= electrons moves closer to the nucleus + to a lower energy level.

Question 7

Fill in the gaps: In an atom, the number of electrons is equal to= the number of _______ in the nucleus.

Answer 7

In an atom, the number of electrons is equal to= the number protons in the nucleus.

Question 8

Do atoms have an overall electrical charge?

Answer 8

No, atoms don’t have an overall electrical charge

Question 9

What is the number of protons in an atom, of an element called?

Answer 9

Answer: atomic number.

Question 10

RECAP: What’s an isotope?

Answer 10

Isotopes are: atoms of the same element, with a different number of neutrons.

Question 11

How do we work out the mass number of an element and the atomic number of an element?

Answer 11

• Think M, for massive. Look for the biggest number in that individual element [of the periodic table]
• atomic number [number of protons]- look at the smallest number

Question 12

What happens to atoms if one or more outer electrons, leaves the atom?

Answer 12

If one or more outer electrons leaves the atom, the atom becomes a positively charged ion.

Question 13

What is an alpha particle?

Hint: same as a helium nucleus

Answer 13

• An alpha particle consists of two neutrons, and two protons [same as a helium nucleus]
• Charge: +2
• Mass number:4
• Atomic number: 2

Question 14

What is a beta particle?

Hint: charge, mass number and atomic number.

Hint: ejected

Answer 14

• A beta particle, is a high speed electron ejected from the nucleus, as a neutron turns into a proton, and an electron
• Charge: -1
• Mass number: 0
• Atomic number: -1

Question 15

What is a gamma ray?

Hint: _______________ radiation from unstable

Answer 15

• A gamma ray, is a electromagnetic radiation emitted from unstable nuclei, in radioactive substances.
• There is no change to the mass or atomic number- [they are both zero]

Question 16

What does ‘activity’ mean ?

Hint: number of unstable… that decay…

Answer 16

• activity is, the number of unstable nuclei in the source, that decay per second

Question 17

What does ‘count rate’ mean?

Hint: per second

Answer 17

• count rate the number of counts per second detected, by a geiger counter

Question 18

What does ‘half life’ mean? [2]

Hint: half of the ___________ nuclei to…

Answer 18

• half life is the average time taken for the number of nuclei of the isotope in a sample to halve OR, the time taken for the count rate to fall half its initial value.

Question 19

What is the equation for amount after n half lives

Answer 19

Amount after n half-life’s= (1/2)^ x initial amount

Question 20

What is the equation for calculating final activity?

Answer 20

Activity= activity ➗ half lifes

Final activity= (calculated activity ➗ beginning activity) ✖️ 100

Question 21

[Easy] What is the relative mass and relative charge of a proton?

Answer 21

Relative mass: 1

Relative charge: +1

Question 22

[Easy] What’s the relative mass and relative charge of a neutron?

Hint: charge is neutral

Answer 22

Relative mass: 1

Relative charge: 0

Question 23

[Easy] What’s the relative mass and relative charge of an electron?

Answer 23

Relative mass: very small/0

Relative charge: -1