WA3 Sec 2G3 Sci Revision

Heat from the Sun reaches Earth by _____.

Answer explanation

Heat from the Sun reaches Earth by radiation.

When you stand next to a black car on a hot day, you feel hot as the heat from the car is transferred to you by _______.

An atom of an element has an atomic number of 11 and a mass number of 35. 

How many protons does this atom have?

Answer explanation

The number of protons in an atom is equal to its atomic number, which in this case is 11.

An atom of an element has an atomic number of 5. 

How many protons does this atom have?

Answer explanation

The atom has 5 protons since the atomic number represents the number of protons in the nucleus.

An atom of an element has an atomic number of 5. 

How many electrons does this atom have?

Answer explanation

An atom with an atomic number of 5 has 5 electrons since the number of electrons equals the atomic number in a neutral atom.

An atom of an element has an atomic number of 11 and a mass number of 35. 

How many electrons does this atom have?

Answer explanation

An atom with atomic number 11 has 11 electrons. The number of electrons is equal to the atomic number of the element.

An atom of an element has an atomic number of 8 and a mass number of 16. 

How many neutrons does this atom have?

Answer explanation

To find the number of neutrons, subtract the atomic number (8) from the mass number (16). Therefore, this atom has 8 neutrons.

An atom of an element has an atomic number of 11 and a mass number of 23. 

How many neutrons does this atom have?

The dot and cross diagram of oxygen is shown. How many electrons does it have?

The dot and cross diagram of Boron is shown. How many electrons does it have?