Answer:
it's b
Explanation:
it's b cause ik I'm not wrong at these I did this when I was a kid and never got it wrong so it's b and will be cause b is the right answer so b it is
Answer:
(a) 2 (b) 4 (c) 4
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
- Digits from 1 to 9 are always significant and have infinite number of significant figures.
- All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
- All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
- All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
- All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
- All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.
As per question,
0.000054 has 2 significant figures.
3.001 x 10⁵ has 4 significant figures.
5.600 has 4 significant figures.
Answer: B. A magnet pulls a nail towards it
Explanation: Out of the list of answers, this is the only answer where a force is acting on an object. the act of the magnet pulling on the nail is the force, and the nail is the object.
Answer:
Explanation:
Given
wavelength of emissions are


Energy is given by

where h=Planck's constant
x=velocity of Light
=wavelength of emission




frequency corresponding to this emission



Energy corresponding to 



frequency corresponding to this emission



Answer:
Answer would be C because combustion does the process of heat. Oxygen is a reactant in a combination reaction, which always produces energy in the form of heat and light. Carbon burns in the presence of oxygen to give carbon dioxide.