Answer:
Elements that are found in the same horizontal row (belong to the same period) in the periodic table, e.g. Fluorine and Neon both have the same energy level of 2.
<em>Note: The question does not specify any two elements.</em>
Explanation:
The modern periodic table is organized into eight vertical columns known as groups and seven horizontal rows known as periods. The atomic number ( number of protons in the nucleus) of elements increases when moving across the periodic table from left to right. The horizontal rows or periods represents an energy levels or the number of electron shells in an element. Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Elements belonging to the same period have the same number of energy level or shells. For example, the elements belonging to Period 2 include lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon. These all have the same number of energy level of 2.
Answer:
The carbon atom has four valence (outermost) electrons. Because of this unique configuration, it is easier for the carbon atom to share its four electrons with another atom or atoms than to lose or gain four electrons.
Explanation:
The carbon atom has four valence (outermost) electrons. Because of this unique configuration, it is easier for the carbon atom to share its four electrons with another atom or atoms than to lose or gain four electrons.
How old is Darren? we need to know his age before we answer
Answer:
Muscles can also receive messages from the brain when the body temperature decreases. They respond by shivering. Shivering causes the muscles to contract and relax quickly. This process generates heat.
Answer:
The hershey chase experiment on bacteriophages showed the genetic information is carried in <u>DNA.</u>
Explanation:
In 1952 Alfred Hershey and Martha Chase provided evidence that DNA is the genetic material. These scientists carried out an experimental work with the T2 virus, a bacteriophage that infects the Escherichia coli bacteria, which reproduces by attaching itself to the outer wall of the bacteria, injecting its DNA into it where it replicates and directs, the synthesis of phage proteins. Phage DNA is encapsulated within proteins and produces phages, which lyse or break the cell and releasing phage from the progeny. They used radioactive forms (isotopes) of phosphorus and sulfur. A radioactive isotope can be used as a marker to identify the location of a specific molecule, because any molecule that contains the isotope is radioactive and therefore easy to detect. The DNA contains phosphorus, but doesn't contain sulfur, therefore phosphorus-32 was used to mark the DNA, instead the protein has sulfur, but not phosphorus, so sulfur-35 was used. Hershey and Chase found that sulfur-35 is outside the cell while phosphorus-32 was inside, indicating that DNA was the physical support of the inheritance. This work allowed the scientists to conclude that it's the DNA and not the protein that enters the bacteria during phage reproduction and that only the DNA is transmitted to the phage of the progeny.
