Answer:
1) A chemical reaction is shown.
SnO2 + H2 → Sn + H2O
What is true about this chemical reaction?
B.
It is unbalanced because the mass of the reactants (number of atoms) is greater than the mass of the products (number of atoms).
2) Read the information about an experiment.
Jadon plans on carrying out an experiment involving the burning of steel wool to illustrate the conservation of mass. Steel wool is made of iron. When it is burned it combines with oxygen to form iron(III) oxide.
Which step in his experiment is the most important if he wants his experiment to correctly demonstrate the conservation of mass?
A.
The steel wool should be burned inside of a sealed jar or other closed system.
Explanation:
The explanation to number 1 is that I selected it in my test and got it.
The explanation the number 2 is from the link below:
https://quizizz.com/admin/quiz/5dee60258f1145001bc02ed5/physical-science-2nd-9-weeks-practice-test-2020
A lava flow it the spread of lava that pours out of a volcano
Answer:
hello can you follow me
Explanation:
In think option B is correct
Answer: option D) phylum
Explanation:
The linnaean system of classification from largest to smallest level is as follows:
Kingdom ---> phylum ---> class ---> order ---> family ---> genus ---> specie.
Since the phylum level consists of organisms with less similar characteristics compared to class, order and genus, we can safely say it has most organisms.
Thus, phylum is the answer.
Answer:
False
Explanation:
In DNA double helix molecule, there are four types of nitrogenous bases: adenine, guanine, cytosine and thymine. Purines (i.e., adenine, guanine) and pyrimidines (i.e., cytosine and thymine) hold DNA strands together via hydrogen bonds. In base pairing, guanine always pairs with cytosine through 3 hydrogen bonds, while adenine always pairs with thymine by 2 hydrogen bonds. Hydrogen bonds are a type of dipole–dipole interaction where a hydrogen atom is covalently bonded to a very electronegative atom (e.g., Nitrogen or Oxygen).
