Answer:
helium Because it's in the 9th grade book
Answer:
6e⁻
Explanation:
Charge in reducing 2 mole of Cr⁶⁺ to Cr³⁺
Cr⁶⁺ + xe⁻ → Cr³⁺
The numbers 6+ and 3+ on the chromium atoms are the oxidation number of the atom.
It shows the number of electrons that has been lost by chromium in an oxidation state.
Cr⁶⁺ shows that it has lost 6 electrons. When an atom loses electrons, the number of protons becomes more. This makes it positively charged in nature.
This analogy goes for Cr³⁺
Therefore, in going from reactants to products, chromium
6+ → 3+
In this kind of expression, the number of atoms must be conserved and the charges too;
2Cr⁶⁺ + xe⁻ → 2Cr³⁺
given 2 moles of Cr;
To balance the charge;
2(6+) + x(-) = 2(3+)
12 - x = 6
x = 6
A charge of 6e⁻ is required to reduce 2 mole of Cr⁶⁺ to Cr³⁺
Speed is the rate at which something goes, and velocity is the average acceleration, which means a car can go slow for a bit, and fast for a bit, and have a velocity of medium. Also, speed is much easier to measure.
Answer:
a. form a hypothesis, conduct an experiment, record data, make a conclusion
Explanation:
Performing scientific investigations involved following the SCIENTIFIC METHOD, which is a rule or guideline followed in order to discover knowledge about natural phenomena. The scientific method has been divided into steps viz:
- Making observation/asking questions: In this case, the problem is HOW ANTS FEED.
- Formulating hypothesis: The hypothesis is a testable explanation given to solve the asked question.
- Testing hypothesis: The hypothesis must be able to be tested via conducting an experiment.
- Analyze result: The results of the test is recorded and analysed as data.
- Make conclusions: The conclusion either accepts or rejects the hypothesis depending on the result of the experiment.
Therefore, based on this; form a hypothesis, conduct an experiment, record data, make a conclusion are the steps Colby should take to best study the feeding patterns of ants
Answer:
Ether is used as a solvent because it is aprotic and can solvate the magnesium ion.
Explanation:
Solubility in Water
Because ethers are polar, they are more soluble in water than alkanes of a similar molecular weight. The slight solubility of ethers in water results from hydrogen bonds between the hydrogen atoms of water molecules and the lone pair electrons of the oxygen atom of ether molecules.
Ethers as Solvents
Ethers such as diethyl ether dissolve a wide range of polar and nonpolar organic compounds. Nonpolar compounds are generally more soluble in diethyl ether than alcohols because ethers do not have a hydrogen bonding network that must be broken up to dissolve the solute. Because diethyl ether has a moderate dipole moment, polar substances dissolve readily in it.
Ethers are aprotic. Thus, basic substances, such as Grignard reagents, can be prepared in diethyl ether or tetrahydrofuran. These ethers solvate the magnesium ion, which is coordinated to the lone pair electrons of diethyl ether or THF. Figure attached, shows the solvation of a Grignard reagent with dietheyl ether.
The lone pair electrons of an ether also stabilize electron deficient species such as BF3 and borane (BH3). For example, the borane-THF complex is used in the hydroboration of alkenes (Section 1
