Hello there.
<span>Which VIIA element doesn't have stable isotopes in nature?
</span>Db. At
Answer:
enthalpy
Explanation:
If it is used with a triangle in front, (delta H), that means the change in enthalpy. Delta H= (m)(s)(Delta T). m=mass of products, s=heat of the products, Delta T = change in temperature.
Hope that helps
Answer:
(1) Chloroplast
Explanation:
Cells of living organisms are made up of certain function-specific structures called ORGANELLES. Some organelles are present in plant cells and absent in animal cells and vice versa. In a plant cell, one notable organelle that allows it perform the photosynthetic process is the CHLOROPLAST.
However, the chloroplast is predominantly found in the LEAF part of a plant. This is because leaf cells are the site of photosynthesis. Hence, according to this question, Joe would be able to tell whether the plant cell was from the leaf or the root by looking for CHLOROPLAST as a differentiating factor in each cell.
Explanation:
1. Explain how groups 1A-8A in the periodic table are organized by their number of valence electrons.
The valence electrons in an atom are the outermost shell electrons. They are the most loosely held electrons in an atom.
Coincidentally, the periodic table of elements divided into vertical groups and horizontal periods can be said to be arranged according to the number of valence electrons.
- Atomic numbers are used to arrange elements on the periodic table.
- Down a group, the number of electronic shell increases. More electrons are added to new energy levels.
- As we move from left to right across a period, the number of electrons in elements increases but electronic shell is the same.
- Down a group electronic shell increases but the number of valence electrons are the same.
- All elements in Group 1A has just one valence electrons, Group 2A has two valence electrons.........Group 8A has eight valence electrons.
- Moving across groups is synonymous to moving from left to right on the periodic table.
- Due to this trend, the periodic table is arranged based on the number of valence electrons.
3. explain how you know the number of valence electrons for each group.
The number of valence electrons in a group is the group number:
Group Number valence electrons
1A 1
2A 2
3A 3
4A 4
5A 5
6A 6
7A 7
8A 8
learn more:
Periodic table brainly.com/question/1971327
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The Second Law of Thermodynamics<span> says that processes that involve the transfer or conversion of heat energy are irreversible.</span><span> ... The First </span>Law of Thermodynamics<span> states that energy cannot be created or destroyed; the total quantity of energy in the universe stays the same.</span>
