Alpha decay involves the loss of an alpha particle, aka a helium nucleus. This results in the mass number of the original element decreasing by 4 and the atomic number decreasing by 2. Assuming 23942u is uranium (92), the resulting element's atomic number is 90, making it thorium.
To present his data on the <span>solubility of three different salts in water at 22°C, bar graph should be used since there are different salts and the only variable is the type of salt used. Line graph and scatter plot use two coordinates or variables and is common to comparing data using the same sample while using histogram to find out data distribution is irrelevant.</span>
Answer:
Salt
Explanation:
salt particles make it harder for water particles to freeze back onto the ice
ice that is in contact with dissolved salt melts faster
Answer:
A hypothesis is something you can test a theory is just a thought that you have.
Answer:

Explanation:
We are given a number of particles and asked to convert to moles.
<h3>1. Convert Particles to Moles </h3>
1 mole of any substance contains the same number of particles (atoms, molecules, formula units) : 6.022 *10²³ or Avogadro's Number. For this question, the particles are not specified.
So, we know that 1 mole of this substance contains 6.022 *10²³ particles. Let's set up a ratio.

We are converting 2.98*10²³ particles to moles, so we multiply the ratio by that value.

The units of particles cancel.



<h3>2. Round</h3>
The original measurement of particles (2.98*10²³) has 3 significant figures, so our answer must have the same.
For the number we found, 3 sig figs is the thousandth place.
The 8 in the ten-thousandth place (0.4948522086) tells us to round the 4 up to a 5 in the thousandth place.

2.98*10²³ particles are equal to approximately <u>0.495 moles.</u>