Answer:
Explanation:
A chemical change, as the name suggests, must result from a change in the chemical makeup and new substances are produced. A very common example is metal rusting.
A physical change can be observed without a change in chemical composition. No new substances are produces. Ripping paper and an ice cube melting are physical changes.
A rubber band stretching is a physical change. No new substances are made and the chemical makeup remains the same.
Answer:
physical
Explanation:
this is a physical action to create a change. does not involve chemicals or elements
Explanation:
Let's consider sulphate radical, the chemical formula is given by SO42−. Here we can see there is a -2 charge on SO4, which means it has -2 valency. Now look at the option (a), phosphate can be written as PO43−. There is -3 charge on PO4, that means it has -3 valency.
Explanation:
molecular formula of sulphate ion is SO₄²⁻
and
the valency of sulphate ion is 2.
6
5
3
2
B. slow
C. variable
D. constant
Answer:
correct answer is option C (constant)
Explanation:
Radioactive decay of radioactive element occur at known rates, the unit of radioactive decay is called half-life. The amount of time a radioactive element takes for half of the parent atoms to decay is known as half-life of a radioactive element
During Radioactive decay radioactive elements emits a particle. It's impossible to predict exactly when a given atom of a substance will emit a particular particle, but the decay rate of a radioactive element over a long period of time is constant.
By radioactive decay scientist can determine the age of that particular element. If radioactive decay will vary than age cannot be determined from radioactive decay.
60.2 mg = _____ g
Answer:
60.2 mg is equal to 0.0602 g.
Explanation:
Given = 60.2 mg
To find : 60.2 mg = ? g
Solution:
We know that in 1 gram there are 1000 milligrams.
1 g = 1000 mg
Then in , 1 mg = 0.001 g
So, 60.2 mg = 60.2 mg 0.001 g=0.0602 g