WorksheetsAtoms and molecules
Total questions: 15
Worksheet time: 13mins
Which correctly describes the smallest amount of an element?
Atom
Molecule
Compound
Proton
What does conservation of matter mean?
Matter cycles through an ecosystem and 10% is lost as you move through each trophic level.
Matter cannot be created, but can be destroyed.
Matter cannot be created nor destroyed, and cycles through ecosystems.
Matter and energy both move through ecosystems with 100% efficiency.
What are atoms composed of?
Protons and electrons.
Protons, neutrons, and electrons.
Neutrons and electrons.
Ions, elements, and compounds.
The valency of nitrogen in NH3 is
1
4
3
2
Mass of 0.5 mole of CO2 is
44gm
33gm
22 gm
55gm
Name two scientist who established the laws of chemical combination
Antoine L Lavoiser and Joseph L Proust
Anthony Lavoiser and Joseph Proust
Anthony L proust and Joseph L Lavoiser
Mr.Hooke and Isaac Newton
which has more number of atoms, 100g of Sodium or 100g of Iron
Sodium
Iron
Fes
Fe
Convert into mole.
i)12g of oxygen gas
0.375
375
37.5
3.75
What is the mass of 1 mol of Nitrogen atoms?
14g
1.4g
1410g
4g
What is the mass of
i)0.2 mole of oxygen atom?
3.2g
32g
45g
320.0g
Convert it into mole
i) 20 g of water
1.23 mole
1.37 mole
1.1 mole
2 moles
2 elements C & D combines to form a compound CD. The same compound is obtained from different experiment. give the law in accordance to above observation
law of conservation of mass
law of constant proportion
law of multiple proportion
