A. actinides do not occur in nature.
dinosaur footprint
Explanation:
A dinosaur footprint is an example of a trace fossil. A trace fossil is a type of fossil that shows the activities of organisms that lived in the past.
- Fossils are the preserved remains of organisms that lived several years ago.
- Fossils are usually found in sedimentary rocks and thick layers of ice in temperate and polar regions.
- Body fossils are the remains of the body parts of an organism that has been preserved. They can be skeletal parts, teeth, eggs e.t.c
- A trace fossil shows the preserved remains of the activities of an organism.
- They can be fingerprints, burrows and borings, feccal pellets e.t.c
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Ionic compounds are formed between oppositely charged ions.
A binary ionic compound is composed of ions of two different elements - one of which is a positive ion(metal), and the other is negative ion (nonmetal).
To write the empirical formula of binary ionic compound we must remember that one ion should be positive and other ion should be negative, then only the correct formula should be written. To write the empirical formula the charges of opposite ions should be criss-crossed.
First empirical formula of binary ionic compound is written between
First Formula would be 
Second empirical formula is between 
Second Formula would be 
Note : When the subscript are same they get cancel out, so 
would be written as 
Third empirical formula is between 
Third Formula would be :
Forth empirical formula is between 
Forth Formula would be : 
or 
Note- The subscript will be simplified and the formula will be written as .
The empirical formula of four binary ionic compounds are : 
The mass of the piece of wood is 35.58 g.
Joule = M × T × C
Where, M = mass
T = change in temperature(42C-23C=19 C)
C = specific heat capacity = 1.716 joules/gram
Substituting the values in the equation,
1160 = M × 19 × 1.716
M = 1160/32.604 = 35.58 g
Therefore, the mass of the piece of wood = 35.58 g
<h3>What is meant by specific heat capacity?</h3>
A material's specific heat capacity, which is defined as its heat capacity divided by its mass, determines how much energy is required to increase a gram's temperature by one degree Celsius (or one Kelvin)
<h3>What is mass?</h3>
Mass is the quantity of matter in a physical body.
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Answer: this is not my own words :)
Learn how factors, such as exposure to the atmosphere, the composition of rock and climate affect the rate of weathering. Weathering is the mechanical or chemical process by which rocks are broken down. The weathering that happens to rocks can be understood by relating it to the digestion of a chocolate chip cookie
One of the factors that affects the rate of weathering is exposure to the atmosphere. ... Another factor that affects the rate of weathering is the composition of rock. Rocks are composed of minerals, which are solid substances found within rocks that have their own distinct chemical composition.
