Answer:
no reaction
Explanation:
becaus aluminum is very reactive than zinc
Answer:
1. The formula NH3 tells us that ammonia is made up of three hydrogen atoms bonded with one nitrogen atom.
2. Physical changes are reversible. Chemical changes lead to modification in chemical composition hence irreversible.
(a) Physical change. Copper wire can be unbent again.
(b) Chemical change. Burning of charcoal leads to the reaction of carbon with oxygen to release carbon dioxide in the air, which cannot be reversed.
(c) Chemical change. The presence of yeast leads to trapping of CO2 in the dough, which makes it rise. The sugar in the dough was consumed in the process, making it irreversible.
3.
(a) Ethanol is a liquid at -30 degC. It becomes vapor at +78 degC, and stays in liquid state between melting and boiling point values.
(b) Neon is a gas at 60 degC as its boiling point is -246 degC.
(c) Sulfur is a solid at 7 deg C. It starts melting only at +115 degC.
(d) In general, 25 degC is considered room temperature (rt). Substances with melting points less than 25 and boiling points greater than 25 will be liquid at rt. In the table, Bromine, Chlorine, Ethanol, Mercury, and Water will be liquids at room temperature.
4. Mass is an extensive property. It depends on the amount of matter in a sample and not on the type of matter present. e.g., 4 grams of salt and 4 grams of sugar are the same (will even look similar), but they are different substances. Hence, mass cannot be used for identification of a sample.
5. Physical changes can also lead to the evolution of a gas. For a change to be considered a chemical reaction, a new substance must be formed (in accordance with the law of conservation of mass). e.g., conversion of liquid water to water vapor is not a chemical change.
6. Gas molecules move freely in space. When stored in a sealed container, these molecules get restricted in that space and are unable to escape. Without a container, the molecules keep moving rapidly and occupy space with no boundaries.
In the case of a solid, the molecules have fixed positions. These can vibrate while staying in the same position but are unable to leave the fixed, compact space they occupy. Hence, they have a fixed shape and do not require a container.
The half life of this radioisotope is 12 hours.
<u>Explanation:</u>
The length of time it requires to break down for an initial half amount or the amount of time taken to transform half of a reactant into product. Half of a particular sample took the time to experience radioactive decay. The time it would take to degrade radioactively into another component or nuclide for half of the atoms of an unstable element or nuclide.
If 1/16 of the sample remains it predicts that there were 4 half-life periods then 16 = 2⁴
4 half-life periods = 48 hours / 4
half-life period = 12 hours.
Answer:
There could be a few answers for this question, but my answer would be two different plants. Maybe a bush on the ground fighting for the energy of the sun with a tall tree. Leaves collect the energy from the sun and convert it to energy usable for the plant. a bush on the ground would be fighting for the sunlight with a tall tree.
2x-1≤x+5
2x≤x+6
x≤6
uhhh I hope that was easy to follow and it helped. anyways, just pretend the ≤ is a = and solve
