Periodic table
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What evidence is used to show that there are protons, neutrons and electrons?
Indirect Evidence
What is indirect Evidence?
Evidence that does not involve direct observation
Neutrons and Protons are what In compared to Electrons
1800x heavier, that’s why the mass of an atom are in the nucleus
What equipment can you use to see an atom?
STM Scanning Tunnelling Microscope
Define Atoms
Smallest part of an atom that can take part in a chemical reaction.
What are electrons attracted to and why?
As electrons are negatively charged they are attracted to the positive protons, in the nucleus. This keeps the electrons in orbit.
Why does the Number of protons equal the number of Electrons?
Good question! Why thankyou :) Well, it’s because of a cool thing called neutral atoms. To be neutral, which atoms are, the negative charges must equal the positive. P:E
What are shells you keep talking about?
They are the orbits, or energy levels that electrons spin around in.
Which shell is the most attracted to the Nucleus?
The first one, as its closest which makes it the lowest energy.
When do electrons have the highest energy?
When they are in the outer shell. They have less of an attraction to the nucleus.
Formula to find maximum number of electrons in a shell..
2n^2 N: number of that shell
What is the ground state for atoms?
The lowest energy form, when the shells are filled up 1st then 2nd and so on.
What happens in a firework?
The explosion energy causes the electrons to jump shells. As they return to the ‘ground state’ energy gets released as light!???????
What’s an element?
A so called, building block from which all substances are made.
What’s a chemical formula? What does this formula tell you- H2O?
A formula that tells you what elements make up the substance and in what proportions. In H2O There are 2 hydrogens bonded to an oxygen.
What does the Number of protons tell you?
Atomic number and electrons
How are element names decided? Eg. For carbon C
• first letter. C for Carbon • 2 logical letters. Mg for magnesium • from their Latin or Greek names. Pb for plumbum (lead) • if they are not confirmed 3 letter UUo.
What is the periodic table?
A way of organising known elements in order of increasing atomic number.
What’s bigger? Protons or Neutrons
Neutrons slightly …