3644000 rounded to 2 significant figures is equivalent to 3.6
Answer:
C. It blocked out sunlight
Explanation:
The asteroid impact 65 million years ago was devastating for lot of the animals and plants, resulting in a mass extinction, most noticeably of the dinosaurs. The impact itself killed a lot of flora and fauna, but it was the effect afterward that was crucial. From this impact, there was so much debris propelled into the atmosphere that the sunlight got blocked. Once this happened, most of the plants died out as they were not able to perform photosynthesis. Because the plants were dying out, the herbivores were left without food, so soon they followed, and because the herbivores died out, the predators died out to because they were left without food. The winners turned out to be the small and not specialized plants and animals.
Answer:a weak acid and a weak base
Explanation:
Answer:
An element
It stays shiny
Explanation:
Pure Gold is an element.
An element is a distinct substance that cannot be split-up into simpler substances. Such substances consists of only one kind of atom.
There are over a hundred elements known to date.
As an element, Gold is classified as a metal due to its very unique set of properties.
One of the indicator that gold does not react with oxygen is that it stays shiny. It does not give rusty look when exposed to air.
Substances that combines with oxygen have a rusty look or change appearance when expose to air. For example, iron.
When calcium carbonate is heated, it breaks down to form calcium oxide and carbon dioxide.
Thermal decomposition is the process in which heat is required.
It is also known as thermolysis.
It is processed in which a compound breaks into two or more products when the heat is supplied.
This reaction is used for the production of oxygen.
This reaction is also used for production of acidic as well as basic oxides.
CaCO3 on thermal decomposition gives:
CaCO3→CaO+CO2
CaO→ Basic oxide.
CO2→ Acidic oxide.
