Answer:
1) Moles of CO 2 = Given mass / Molecular mass of CO 2 = 4.4 / 44 = 0.1 mole. 2) Molecules of CO2 in 0.1 moles of CO2 = 0.1 x 6.023 x 10 23 = 6.023 x 10 22 molecules 3) 44 gram (molecular wt of CO 2) contains 2 moles atom of oxygen therefore 4.4 gram of CO2 will contain = 2 /44 *4.4 = 0.2 moles atom of Oxygen.
If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.
Answer:
Used without adult supervision
Used without goggles
Used without gloves
Answer:
False
Explanation:
A significant number is a number that is used to express the accuracy in a measurement. There are some rules that binds the identification of significant figures when reporting a scientific measurement.
- All non-zero numbers are significant
- Zeros in between two digits are significant.
- Zeros to the right of the decimal are significant.
- Leading zeros are just place holders and are not significant.
- Trailing zero in a whole number with decimal is significant
- Trailing zero without a decimal is not significant.
source: http://ccnmtl.columbia.edu/projects/mmt/frontiers/web/chapter_5/6665.html
We can see that not all zeros in a measurement is significant. For example, 540 has 2 significant numbers because the zero is not significant but 540.2 has 4 significant numbers.
