Answer:
B, C
Explanation:
The atoms or ions with the valid Lewis dot structures are B and C.
In A;
The Lewis structure of the carbon is correct. Each of the four dots represent the four valence electrons.
The nitrogen with one dot on top, left and to the bottom and has a charge of minus 3 is wrong. For it to have a charge of -3 it must have 8 lewis dots ( two on the top, right, bottom and to the left)
The nitrogen with four dots (on top, right, bottom and to the left) is wrong.
In B;
An oxygen has two dots on top and bottom and one dot to the left and to the right. This is correct , the 6 dots represent the valence electrons of oxygen.
In C;
A carbon has two dots on top, right, bottom and to the left and a charge of plus four. This is correct because the charge indicates that it has gained four extra electrons so its valence electrons is now 8.
In D;
An oxygen has two dots on top, left and to the bottom and a charge of minus 2. This is wrong because the lewis dots are incomplete. Two dots are missing.
Answer:
116.88 g
Explanation:
Step 1: Write the balanced equation for the synthesis of NaCl
Na + 1/2 Cl₂ ⇒ NaCl
Step 2: Calculate the moles corresponding to 45.978 g of Na
The molar mass of Na is 22.990 g/mol.
45.978 g × 1 mol/22.990 g = 1.9999 mol
Step 3: Calculate the number of moles of NaCl formed from 1.9999 moles of Na
The molar ratio of Na to NaCl is 1:1. The moles of NaCl formed are 1/1 × 1.9999 mol = 1.9999 mol.
Step 4: Calculate the mass corresponding to 1.9999 moles of NaCl
The molar mass of NaCl is 58.443 g/mol.
1.9999 mol × 58.443 g/mol = 116.88 g
Answer:
Its a chemical change.
Explanation:
When baking soda and vinegar are mixed bubbles formed and new product is formed by both reactant. So its a chemical change because in a chemical change new substances are formed.
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
These changes are irreversible
These changes occur due to chemical reactions
These may not be observed with naked eye
Example:
Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood
Boiling of egg: that change the chemical composition of protein in the egg .
The reaction of Hydrogen and oxygen:
H 2 (g) + O 2 (g) -------------------------------------> 2H 2O (l)
Specialized periodicals in which scientists publish the results of their works are called scientific journals.
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In educational publishing, a scientific journal is a periodical book intended to similarly the progress of technology, typically by way of reporting new studies.
Journal articles may include original research, re-analyses of studies, opinions of literature in a selected place, proposals of new but untested theories, or opinion pieces.
These scientific journals include the following.
- original articles,
- case reports,
- technical notes,
- pictorial essays,
- reviews,
- commentaries
- editorials.
Learn more about scientific journals here brainly.com/question/14443228
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