Answer:
The conversion of liquid water into gaseous water is a chemical change
Explanation:
A chemical change occurs when there is a chemical reaction, so there'll be changed in the compounds, such as forming new ones, forming its elements, or elements forming compounds.
A physical change occurs when there is a change in the state of aggregation of the compound, it means that it changes its physical state. Solid for liquid, liquid for solid, liquid for gas, gas for liquid, solid for gas, and gas for solid are the physical changes.
So the evaporation of water, or its conversion in gaseous water, is a physical change, not a chemical change.
<u>Answer:</u> The for the reaction is 51.8 kJ.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The chemical equation for the reaction of carbon and water follows:
The intermediate balanced chemical reaction are:
(1) ( × 2)
(2) ( × 2)
(3)
The expression for enthalpy of the reaction follows:
Putting values in above equation, we get:
Hence, the for the reaction is 51.8 kJ.
Answer:
B.
Explanation:
when you use punnett squares, you cross the different genes with themselves. if T is in the first box on both sides, the genome will be TT. if the box lines up to tt, it will be tt. the boxes on the left use the genes' first letter and the boxes on the right use the second letter.
Answer:
C.)organs are a group of two or more different types of tissues that work together to perform a specific function
Explanation:
Cells of similar function are grouped together into tissues. For example, cardiac muscle tissue is present only in the heart, and made up of specialised cells called cardiomyocytes, or cardiac muscle cells. These cells contract to pump blood around the body.
The heart is an organ, consisting of multiple types of tissue including cardiac muscle tissue, connective tissue, blood vessels and epithelial tissue. Therefore, organs represent a group of at least two types of tissue that work together to carry out functions in the body.
Answer: Polythene
Polythene is a synthetic polymer classified as plastics.
Explanation:
Polythene is formed artificially from several repeating units of ethene molecules (monomers) in a reaction known as polymerization.
The polyethene can be represented as [CH2-CH2]n, where n is thousands to ten thousands unit of ethene.
It is used to make
- plastic bags,
- cable insulators
- plastic crates etc
Thus, polythene is a synthetic polymer of ethene, and classified as plastics.