The second one, b synthesis reaction
Answer:
8
Explanation:
1 mole = 6.02 × 10²³ atoms
? moles = 4.816 × 10²⁴ atoms.
? Moles = 4.816 × 10²⁴ ÷ 6.02 × 10²³
? Moles = 8 moles
8 moles of aluminum = 4.816 × 10²⁴
Answer:
The central atom has 3 electron domains.
Explanation:
According to the Valence Shell electron pair repulsion theory (VSEPR) put forward by Gillespie and Nyholm in 1957, the shape of a molecule is determined by repulsion between all the electron pairs (electron domains) present in the valence shell.
The electron pairs or electron domains are known to position themselves as far apart in space as possible in order to minimize repulsions.
Hence, when the central atom of a molecule contains three electron domains, they are positioned at an angle of 120° from each other to minimize repulsions. Hence the answer.
Answer:
Because it can cause health problems or injuries to our sense organs.
Explanation:
Chemicals in the laboratory are made up of different constituents, which may be dangerous or injurious to health. This is the reason why safety measures or precautions have to be taken when working in the laboratory. One of those safety measures is that "one should never use taste, touch, or smell to identify an unknown chemical".
This is so because a chemical that is unknown amounts to the fact that what such chemical contains is unknown, hence, the chemical might have the ability to cause harm or injuries to the sense organ. For example, a conc. acid that is tasted will burn the tongue etc.
Answer:Light bounces off of the mirror and then appears to come from behind the mirror.
Explanation:Plane mirrors form images that are virtual, upright and the same size and shape as the object it is reflecting.
When rays of light from the object hits a plane mirror they bounces off the mirror,that is they undergo reflection, and appear to originate from behind the mirror, resulting to the formation of a virtual image.
The image formed appears to be behind the plane in which the mirror lies. A virtual image is an image that is formed at a location from which the rays of light appear to come from. The image can not be formed on a screen..
