Answer:
An atom has a nucleus, made up protons and neutrons, which is surrounded by a cloud of electrons.
Explanation:
An atom is the smallest indivisible part of any element that takes place in a chemical reactions.
These are the fundamental building blocks of every element and even compounds.
- There are three known subatomic particles found within an atom.
- Electrons are the negatively charged particles in an atom
- Protons are the positively charged particles of an atom
- Neutrons do not carry any charges.
Both protons and neutrons are located within the tiny space called nucleus at the center of an atom.
Electrons moves round in orbitals at the spaces outside of the nucleus.
Option c. They prove that structure and location of remains of organisms depict past events.
Answer:
0.24%
Explanation:
A toothpaste contains 0.24% by mass sodium fluoride (NaF) used to prevent dental caries and 0.30% by mass triclosan, C12H7Cl3O2, a preservative and antigingivitis agent. One tube contains 119 g of toothpaste. (6.4, 6.5) Components in toothpaste include triclosan and NaF.a. How many moles of NaF are in the tube of toothpaste?b. How many fluoride ions (F?) are in the tube of toothpaste?c. How many grams of sodium ion (Na+) are in 1.50 g of toothpaste?d. How many molecules of triclosan are in the tube of toothpaste?Solution 124CQStep 1 of 4:Given:Mass of toothpaste = 119 g. Mass percent of sodium fluoride (NaF) = 0.24%Mass percent of triclosan (C12H7Cl3O2) = 0.30%a. Here, we are asked to find the number of moles of NaF in the tube of toothpaste.Mass percent of sodium fluoride (NaF) = 0.24%First, let’s find the mass of NaF in the tube: = 119 g = 0.2856 grams Molar mass of NaF = 41.98 g/mol This means, 1 mol NaF = 41.98 g. So, the mole-mass factor is: and Therefore, number of moles of NaF will be: = 0.2856 g NaF = 0.00680 mol NaFHence, the number of moles of NaF in 119g toothpaste is 0.00680 moles. ________________
