Sawing a board in half is a physical change not a chemical change the board doesnt change wood or whatever material it is is still would still be wood
If it were burned it would be a chemical change but its properties stay the same atomically so thats why its not a chemical change.
Answer:
9) Substitution Reaction
10) Covalent Bond
11) Ionic Bond
12) Covalent Bond
13) Ionic Bond
14) 9 atoms
Explanation:
9) Substitution Reaction: Substitution reaction is a chemical reaction in which one atom, ion or species replaced by another atom, ion or species
10) Covalent Bond: Covalent bond is a bond that formed between two nonmetals, when both the species are non metal, the electronegativity of both the nonmetals are comparatively same, hence any of both do not pulls completely electron of other & the bond is formed by the sharing of electron.
11) Ionic Bond: We know that nonmetals have high electronegativity than those of metals, due to high electronegativity non metals pulls the electrons of metals but there is enough interaction that non metal do not escape after pulling the electron, & an ionic bond generates where non metals possess negative charge & positive charge goes to metal.
12) Covalent Bond: The bond formed between two atoms having less electronegativity diffrence by sharing of electron pair is know as covalent bond. for e.g the Carbon - Hydrogen bond in methane (CH4) molecule is covalent bonded because the electronegativity of carbon is 2.5 & that of hydrogen is 2.1 which is almost close, hence the bond formed is covalent.
13) Ionic Bond: The bond formed between two atoms having high electronegativity diffrence & the bond formed is due to complete transfer of electron by one species. For e.g. NaCl the sodium is a metal having electronegativity 0.9 and chlorine is non metal having electronegativity 3.0 the electronegativity diffrence is too high, hence the chlorine behaves as Cl- ion that of sodium as Na+, both the components behaves as ion but they are bonded &that bond is called as Ionic bond.
14) 9 Atoms: One molecule of water (H2O) posses three atoms, two hydrogen atoms & one oxygen atom, the number of atoms in 3 molecules of water 3×3 = 9 atoms.
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Answer:
Explanation:
Take a random sample of nuts from the jar. Let's take two handfuls, after shaking the jar and mixing the nuts thoroughly. Separate the nuts into almonds and cashews. Count each pile, then do the following calculation (these numbers are random, for example only).
<u> Count</u> <u>Percentage %</u>
Almonds 38 (38)/(87)x100
Cashews <u> 49</u> 49/87x100
87 87/87 = 100%
Ratio of Almonds to Cashews: <u>38/49</u>
Plastic bags are made up of plastic film, non-woven fabric, or plastic textile. The molecules that are present in plastic bags are polymers. Polymers are large molecules made up of repeating units called monomers.
I know this isn't much, but I hope it helps! :)
