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Question
Define the following term with an example.
Element
Solution
Element: It is a substance that cannot be broken down into simpler substance by chemical means
Ex.: Oxygen, Hydrogen, Gold & Helium.
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RELATED QUESTIONS
MATCH THE COLUMNAS
| 1. Jpham Dalton | a. Neutrons |
| 2. Atom | b. Model of the atom |
| 3. Chadwick | c.The atomic theory of matter |
| 4. Rutherfrod | d. Positively charged |
| 5. Protons | e. Electricity neutral |
| 6. Nuclear fusion | f. Generator of electricity |
| 7.Gamma -rays | g. High penetrating power |
| h.Energy in sun |
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Write the names of `"FeS"` compounds :
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An ion with negative charge is called _______
Define: Chemical bond
What are orbits or shells ?
Define: Covalent bond
Give two examples for each of ionic and covalent bond.
Write electronic configuration of oxygen, fluorine, sodium, silicon, argon.
Who originated the word ‘atom’ ?
What does the word ‘atom’ mean?
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If an atom gains an electron, it is called an _______
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An excess of electrons produces a ________ charge.
Fill in the following blanks with suitable words :
In water, the proportion of oxygen and hydrogen is .............. by mass.
State two observations which show that atom is not indivisible.
How many atoms are there in exactly 12 g of carbon-12 element ? (C = 12 u)
Draw diagrams representing the atomic structures of the following:
- Sodium atom
- Chlorine ion
- Carbon atom
- Oxygen ion
Draw the electron dot structure of this compound.
Assertion: An atom is electrically neutral.
Reason: Atoms have equal number of protons and electrons.
Draw the structure of an atom and explain the position of the sub-atomic particles.
Project.
To have an idea of what atoms are, students can be asked to construct atoms using pipe cleaners (thin metal wires-electron shells), pompoms (balls-different colours for protons and neutrons) and beads (electrons). Students will love and enjoy putting them together and they look great hanging from the ceiling in the classroom.
Define the following term with an example.
Non-metal
Define the following term with an example.
Metalloid
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Dalton’s atomic theory successfully explained
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportions
The graphite refill used is pencil is made of element called ______.
The smallest unit of an element is ______.
______ is a substance that is made up of three oxygen atoms chemically combined.
Atoms have a radius of the order ______.
